diff --git a/c/Makefile b/c/Makefile
index 3a185ba..b4c354e 100644
--- a/c/Makefile
+++ b/c/Makefile
@@ -9,7 +9,7 @@ VENDOR_SRCS = vendor/linenoise/linenoise.c
 OBJS = $(patsubst %.c,$(BUILDDIR)/%.o,$(SRCS)) $(patsubst %.c,$(BUILDDIR)/%.o,$(VENDOR_SRCS))
 TARGET = ../dist/cagent
 
-.PHONY: all clean
+.PHONY: all clean test-continue
 
 all: $(TARGET)
 
@@ -32,13 +32,17 @@ $(BUILDDIR)/%.o: %.c tools_embed.h
 	$(CC) $(CFLAGS) -c -o $@ $<
 
 clean:
-	rm -rf $(BUILDDIR) $(TARGET) tools_embed.h test_classify
+	rm -rf $(BUILDDIR) $(TARGET) tools_embed.h test_classify test_continue
 
 test-classify: test_classify.c
 	$(MAKE) $(BUILDDIR)/tools_test.o CFLAGS="$(CFLAGS) -DTEST_CLASSIFY" OBJS="$(filter-out $(BUILDDIR)/cagent.o $(BUILDDIR)/tools.o,$(OBJS)) $(BUILDDIR)/tools_test.o"
 	$(CC) $(CFLAGS) -DTEST_CLASSIFY -o test_classify test_classify.c $(filter-out $(BUILDDIR)/cagent.o $(BUILDDIR)/tools.o,$(OBJS)) $(BUILDDIR)/tools_test.o $(LDFLAGS)
 	@./test_classify
 
+test-continue: test_continue.c store.c util.c json.c
+	$(CC) $(CFLAGS) -o test_continue test_continue.c store.c util.c json.c
+	@./test_continue
+
 $(BUILDDIR)/tools_test.o: tools.c tools.h agent.h msgqueue.h protocol.h json.h util.h
 	$(CC) $(CFLAGS) -DTEST_CLASSIFY -c -o $@ tools.c
 
diff --git a/c/store.c b/c/store.c
index e8a1346..77660bf 100644
--- a/c/store.c
+++ b/c/store.c
@@ -228,7 +228,7 @@ char *store_session_resolve_continue(const char *home, const char *cwd) {
 
     struct dirent *entry;
     while ((entry = readdir(dir)) != NULL) {
-        if (entry->d_name[0] == '.') continue;
+        if (entry->d_name[0] == '.' || strncmp(entry->d_name, "sub_", 4) == 0) continue;
         /* 尝试解析目录名为时间戳: YYYYMMDD-HHMMSS-XXXX */
         struct stat st;
         sb_truncate(&buf, 0);
diff --git a/c/test_continue.c b/c/test_continue.c
new file mode 100644
index 0000000..15c2241
--- /dev/null
+++ b/c/test_continue.c
@@ -0,0 +1,115 @@
+#include "store.h"
+#include "util.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/time.h>
+#include <time.h>
+#include <unistd.h>
+
+static int failures = 0;
+
+static void check(int condition, const char *message) {
+    if (condition) {
+        printf("PASS: %s\n", message);
+    } else {
+        fprintf(stderr, "FAIL: %s\n", message);
+        failures++;
+    }
+}
+
+static char *make_temp_dir(const char *label) {
+    char *path = NULL;
+    if (asprintf(&path, "/tmp/cagent-%s-XXXXXX", label) < 0) return NULL;
+    if (!mkdtemp(path)) {
+        free(path);
+        return NULL;
+    }
+    return path;
+}
+
+static void set_mtime(const char *path, time_t when) {
+    struct timeval times[2] = {{when, 0}, {when, 0}};
+    if (utimes(path, times) != 0) {
+        perror("utimes");
+        exit(1);
+    }
+}
+
+static void test_continue_skips_sub_sessions(void) {
+    char *home = make_temp_dir("continue-skip-sub");
+    char *cwd = util_path_join(home, "project");
+    util_mkdirs(cwd, 0755);
+    char *key = store_session_project_key(cwd);
+    char *project_dir = NULL;
+    asprintf(&project_dir, "%s/.bash-agent/projects/%s", home, key);
+    char *normal_dir = util_path_join(project_dir, "normal-session");
+    char *sub_dir = util_path_join(project_dir, "sub_latest");
+    util_mkdirs(normal_dir, 0755);
+    util_mkdirs(sub_dir, 0755);
+    char *normal_events = util_path_join(normal_dir, "events.jsonl");
+    char *sub_events = util_path_join(sub_dir, "events.jsonl");
+    util_write_file(normal_events, "{}\n");
+    util_write_file(sub_events, "{}\n");
+    time_t now = time(NULL);
+    set_mtime(normal_events, now - 60);
+    set_mtime(sub_events, now);
+
+    char *resolved = store_session_resolve_continue(home, cwd);
+    check(resolved && strcmp(resolved, "normal-session") == 0,
+          "continue skips a newer sub session");
+
+    free(resolved);
+    free(sub_events);
+    free(normal_events);
+    free(sub_dir);
+    free(normal_dir);
+    free(project_dir);
+    free(key);
+    free(cwd);
+    free(home);
+}
+
+static void test_continue_rejects_only_sub_sessions(void) {
+    char *home = make_temp_dir("continue-only-sub");
+    char *cwd = util_path_join(home, "project");
+    util_mkdirs(cwd, 0755);
+    char *key = store_session_project_key(cwd);
+    char *project_dir = NULL;
+    asprintf(&project_dir, "%s/.bash-agent/projects/%s", home, key);
+    char *sub_dir = util_path_join(project_dir, "sub_only");
+    util_mkdirs(sub_dir, 0755);
+
+    char *resolved = store_session_resolve_continue(home, cwd);
+    check(resolved == NULL, "continue finds no session when only sub sessions exist");
+
+    free(resolved);
+    free(sub_dir);
+    free(project_dir);
+    free(key);
+    free(cwd);
+    free(home);
+}
+
+static void test_explicit_sub_session_paths_remain_available(void) {
+    char *home = make_temp_dir("explicit-sub");
+    char *cwd = util_path_join(home, "project");
+    util_mkdirs(cwd, 0755);
+    SessionPaths paths = store_session_paths_for(home, cwd, "sub_manual");
+    const char *name = strrchr(paths.session_dir, '/');
+    check(name && strcmp(name + 1, "sub_manual") == 0,
+          "explicit sub session IDs remain available");
+
+    store_session_paths_free(&paths);
+    free(cwd);
+    free(home);
+}
+
+int main(void) {
+    test_continue_skips_sub_sessions();
+    test_continue_rejects_only_sub_sessions();
+    test_explicit_sub_session_paths_remain_available();
+    return failures == 0 ? 0 : 1;
+}
diff --git a/go/agent_test.go b/go/agent_test.go
index 8f3457e..7143bc0 100644
--- a/go/agent_test.go
+++ b/go/agent_test.go
@@ -9,6 +9,7 @@ import (
 	"path/filepath"
 	"strings"
 	"testing"
+	"time"
 )
 
 // ─── 配置测试 ───
@@ -163,8 +164,8 @@ func TestToolClassifyBashRequiredModeCWD(t *testing.T) {
 		// 可信内部目录
 		"cat > /tmp/test.go << EOF":                           "0004",
 		"cat /tmp-other/file":                                 "0400",
-		"cat /tmp/../etc/hosts":                                "4000",
-		"echo hi > /tmp/../etc/native-file-mode-test":          "2000",
+		"cat /tmp/../etc/hosts":                               "4000",
+		"echo hi > /tmp/../etc/native-file-mode-test":         "2000",
 		"cat > SAMPLE_HOME/.bash-agent/projects/session/file": "0004",
 		"cat SAMPLE_HOME/.bash-agent/projects-copy/file":      "0400",
 		// /dev/null
@@ -310,6 +311,72 @@ func TestFileStoreInit(t *testing.T) {
 	}
 }
 
+func TestFileStoreResolveContinueSkipsSubSessions(t *testing.T) {
+	home := t.TempDir()
+	cwd := t.TempDir()
+	store := NewFileStore(home, cwd)
+	projectDir := store.GetDir()
+
+	normalDir := filepath.Join(projectDir, "normal-session")
+	subDir := filepath.Join(projectDir, "sub_latest")
+	if err := os.MkdirAll(normalDir, 0755); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.MkdirAll(subDir, 0755); err != nil {
+		t.Fatal(err)
+	}
+	now := time.Now()
+	normalEvents := filepath.Join(normalDir, "events.jsonl")
+	subEvents := filepath.Join(subDir, "events.jsonl")
+	if err := os.WriteFile(normalEvents, []byte("{}\n"), 0644); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.WriteFile(subEvents, []byte("{}\n"), 0644); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.Chtimes(normalEvents, now.Add(-time.Hour), now.Add(-time.Hour)); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.Chtimes(subEvents, now, now); err != nil {
+		t.Fatal(err)
+	}
+
+	id, err := store.ResolveContinue()
+	if err != nil {
+		t.Fatalf("ResolveContinue: %v", err)
+	}
+	if id != "normal-session" {
+		t.Fatalf("ResolveContinue = %q, want normal-session", id)
+	}
+}
+
+func TestFileStoreResolveContinueWithOnlySubSessionsCreatesNewID(t *testing.T) {
+	home := t.TempDir()
+	cwd := t.TempDir()
+	store := NewFileStore(home, cwd)
+	if err := os.MkdirAll(filepath.Join(store.GetDir(), "sub_only"), 0755); err != nil {
+		t.Fatal(err)
+	}
+
+	id, err := store.ResolveContinue()
+	if err != nil {
+		t.Fatalf("ResolveContinue: %v", err)
+	}
+	if id == "" || strings.HasPrefix(id, "sub_") {
+		t.Fatalf("ResolveContinue = %q, want a new regular session ID", id)
+	}
+}
+
+func TestFileStoreExplicitSubSessionRemainsUsable(t *testing.T) {
+	store := NewFileStore(t.TempDir(), t.TempDir())
+	if err := store.Init("sub_manual"); err != nil {
+		t.Fatalf("Init explicit sub session: %v", err)
+	}
+	if store.SessionID() != "sub_manual" {
+		t.Fatalf("SessionID = %q, want sub_manual", store.SessionID())
+	}
+}
+
 func TestFileStoreConversation(t *testing.T) {
 	store := newTestStore(t)
 
diff --git a/go/store.go b/go/store.go
index f92f9a3..b28bfec 100644
--- a/go/store.go
+++ b/go/store.go
@@ -231,7 +231,7 @@ func (s *FileStore) GetLatestDir() (string, error) {
 	var latest string
 	var latestTs int64
 	for _, e := range entries {
-		if !e.IsDir() {
+		if !e.IsDir() || strings.HasPrefix(e.Name(), "sub_") {
 			continue
 		}
 		/* 优先用 events.jsonl 的 mtime，fallback 到目录 mtime（对齐 bash/rust） */
diff --git a/rust/src/store.rs b/rust/src/store.rs
index a32f969..00d8ac0 100644
--- a/rust/src/store.rs
+++ b/rust/src/store.rs
@@ -605,6 +605,9 @@ use std::path::{Path, PathBuf};
                 continue;
             }
             let name = entry.file_name().to_string_lossy().to_string();
+            if name.starts_with("sub_") {
+                continue;
+            }
             let mt = session_activity_mod_time(&entry.path())?;
             match &newest {
                 Some((ts, _)) if *ts >= mt => {}
@@ -625,3 +628,55 @@ use std::path::{Path, PathBuf};
         }
         Ok(fs::metadata(session_dir)?.modified()?)
     }
+
+#[cfg(test)]
+mod continue_tests {
+    use super::*;
+    use std::time::{Duration, SystemTime, UNIX_EPOCH};
+
+    fn test_root(name: &str) -> PathBuf {
+        let nonce = SystemTime::now()
+            .duration_since(UNIX_EPOCH)
+            .unwrap()
+            .as_nanos();
+        std::env::temp_dir().join(format!("rustagent-{name}-{}-{nonce}", std::process::id()))
+    }
+
+    #[test]
+    fn continue_skips_newer_sub_session() {
+        let home = test_root("continue-skip-sub");
+        let cwd = home.join("project");
+        fs::create_dir_all(&cwd).unwrap();
+        let project_dir = home.join(".bash-agent/projects").join(project_key(&cwd));
+        let normal = project_dir.join("normal-session");
+        let sub = project_dir.join("sub_latest");
+        fs::create_dir_all(&normal).unwrap();
+        std::thread::sleep(Duration::from_millis(20));
+        fs::create_dir_all(&sub).unwrap();
+
+        assert_eq!(continue_session(&home, &cwd).unwrap(), "normal-session");
+        let _ = fs::remove_dir_all(home);
+    }
+
+    #[test]
+    fn continue_rejects_projects_with_only_sub_sessions() {
+        let home = test_root("continue-only-sub");
+        let cwd = home.join("project");
+        fs::create_dir_all(&cwd).unwrap();
+        let project_dir = home.join(".bash-agent/projects").join(project_key(&cwd));
+        fs::create_dir_all(project_dir.join("sub_only")).unwrap();
+
+        assert!(continue_session(&home, &cwd).is_err());
+        let _ = fs::remove_dir_all(home);
+    }
+
+    #[test]
+    fn explicit_sub_session_paths_remain_available() {
+        let home = test_root("explicit-sub");
+        let cwd = home.join("project");
+        let paths = paths_for(&home, &cwd, "sub_manual");
+
+        assert_eq!(paths.session_dir.file_name().unwrap(), "sub_manual");
+        let _ = fs::remove_dir_all(home);
+    }
+}
diff --git a/src/agent.sh b/src/agent.sh
index 94b14c7..dbada6a 100755
--- a/src/agent.sh
+++ b/src/agent.sh
@@ -418,7 +418,7 @@ store_session_get_dir() {
 }
 
 store_session_get_latest_dir() {
-    local project_dir latest="" latest_ts=0 dir ts stat_cmd
+    local project_dir latest="" latest_ts=0 dir name ts stat_cmd
     project_dir="$(store_session_get_dir)"
     [[ -d "$project_dir" ]] || return 1
     if stat -c "%Y" "$project_dir" &>/dev/null; then
@@ -428,6 +428,8 @@ store_session_get_latest_dir() {
     fi
     for dir in "$project_dir"/*/; do
         [[ -d "$dir" ]] || continue
+        name="$(basename "${dir%/}")"
+        [[ "$name" == sub_* ]] && continue
         local target="$dir"
         [[ -f "$dir/events.jsonl" ]] && target="$dir/events.jsonl"
         ts=$("${stat_cmd[@]}" "$target" 2>/dev/null || echo 0)
diff --git a/tests/test_continue_sessions.sh b/tests/test_continue_sessions.sh
new file mode 100644
index 0000000..15ee461
--- /dev/null
+++ b/tests/test_continue_sessions.sh
@@ -0,0 +1,110 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+ROOT_DIR="$(cd "$(dirname "$0")/.." && pwd)"
+AGENT="${AGENT:-$ROOT_DIR/src/agent.sh}"
+case "$AGENT" in
+    /*) ;;
+    *) AGENT="$ROOT_DIR/${AGENT#./}" ;;
+esac
+
+TMP_ROOT=$(mktemp -d "${TMPDIR:-/tmp}/bash-agent-continue-test.XXXXXX")
+PORT_FILE="$TMP_ROOT/port"
+cleanup() {
+    if [[ -n "${SERVER_PID:-}" ]]; then
+        kill "$SERVER_PID" 2>/dev/null || true
+        wait "$SERVER_PID" 2>/dev/null || true
+    fi
+    rm -rf "$TMP_ROOT"
+}
+trap cleanup EXIT
+
+python3 - "$PORT_FILE" <<'PY' &
+import http.server
+import sys
+
+port_file = sys.argv[1]
+
+class Handler(http.server.BaseHTTPRequestHandler):
+    def do_POST(self):
+        length = int(self.headers.get("Content-Length", "0"))
+        self.rfile.read(length)
+        body = b'{"error":{"message":"test stop"}}'
+        self.send_response(422)
+        self.send_header("Content-Type", "application/json")
+        self.send_header("Content-Length", str(len(body)))
+        self.end_headers()
+        self.wfile.write(body)
+
+    def log_message(self, *_args):
+        pass
+
+server = http.server.ThreadingHTTPServer(("127.0.0.1", 0), Handler)
+with open(port_file, "w", encoding="utf-8") as f:
+    f.write(str(server.server_port))
+server.serve_forever()
+PY
+SERVER_PID=$!
+for _ in {1..100}; do
+    [[ -s "$PORT_FILE" ]] && break
+    sleep 0.02
+done
+[[ -s "$PORT_FILE" ]] || { echo "mock server failed to start" >&2; exit 1; }
+PORT=$(cat "$PORT_FILE")
+
+project_key() {
+    local cwd
+    cwd=$(cd "$1" && pwd -P)
+    cwd="${cwd#/}"
+    cwd="${cwd//\//-}"
+    cwd=$(printf '%s' "$cwd" | awk '{ gsub(/[^A-Za-z0-9._-]/, "-"); gsub(/-+/, "-", $0); sub(/^-+/, "", $0); sub(/-+$/, "", $0); print }')
+    printf -- '-%s' "$cwd"
+}
+
+run_agent() {
+    local home=$1 cwd=$2
+    shift 2
+    (
+        cd "$cwd"
+        BASH_AGENT_HOME="$home" HOME="$home" "$AGENT" \
+            -p claude --base-url "http://127.0.0.1:$PORT/v1" \
+            -m test --api-key test "$@" >/dev/null 2>&1 || true
+    )
+}
+
+# 最新活动目录是 SubAgent 会话时，自动续聊必须选择普通会话。
+home="$TMP_ROOT/latest-sub-home"
+cwd="$TMP_ROOT/latest-sub-project"
+mkdir -p "$home" "$cwd"
+project_dir="$home/.bash-agent/projects/$(project_key "$cwd")"
+mkdir -p "$project_dir/normal-session" "$project_dir/sub_latest"
+printf '{}\n' > "$project_dir/normal-session/events.jsonl"
+printf '{}\n' > "$project_dir/sub_latest/events.jsonl"
+touch -t 202401010101 "$project_dir/normal-session/events.jsonl"
+touch -t 202501010101 "$project_dir/sub_latest/events.jsonl"
+run_agent "$home" "$cwd" --continue "continue-selection-marker"
+grep -q 'continue-selection-marker' "$project_dir/normal-session/conversation.jsonl"
+[[ ! -f "$project_dir/sub_latest/conversation.jsonl" ]]
+
+# 只有 SubAgent 会话时，自动续聊必须创建新的普通会话。
+home="$TMP_ROOT/only-sub-home"
+cwd="$TMP_ROOT/only-sub-project"
+mkdir -p "$home" "$cwd"
+project_dir="$home/.bash-agent/projects/$(project_key "$cwd")"
+mkdir -p "$project_dir/sub_only"
+printf '{}\n' > "$project_dir/sub_only/events.jsonl"
+run_agent "$home" "$cwd" --continue "new-session-marker"
+regular_session=$(find "$project_dir" -mindepth 1 -maxdepth 1 -type d ! -name 'sub_*' -print | head -1)
+regular_count=$(find "$project_dir" -mindepth 1 -maxdepth 1 -type d ! -name 'sub_*' -print | wc -l | tr -d ' ')
+[[ "$regular_count" -eq 1 ]]
+grep -q 'new-session-marker' "$regular_session/conversation.jsonl"
+
+# 显式指定 SubAgent session_id 时仍允许进入。
+home="$TMP_ROOT/explicit-sub-home"
+cwd="$TMP_ROOT/explicit-sub-project"
+mkdir -p "$home" "$cwd"
+project_dir="$home/.bash-agent/projects/$(project_key "$cwd")"
+run_agent "$home" "$cwd" --session sub_manual "explicit-sub-marker"
+grep -q 'explicit-sub-marker' "$project_dir/sub_manual/conversation.jsonl"
+
+printf 'PASS: %s continue session filtering\n' "$(basename "$AGENT")"