diff --git a/src/sources/topsql/upstream/tidb/parser.rs b/src/sources/topsql/upstream/tidb/parser.rs
index ec610981..96a7b7b4 100644
--- a/src/sources/topsql/upstream/tidb/parser.rs
+++ b/src/sources/topsql/upstream/tidb/parser.rs
@@ -405,7 +405,10 @@ impl TopSqlSubResponseParser {
                 &[
                     (LABEL_NAME, METRIC_NAME_SQL_META.to_owned()),
                     (LABEL_SQL_DIGEST, hex::encode_upper(sql_meta.sql_digest)),
-                    (LABEL_NORMALIZED_SQL, sql_meta.normalized_sql),
+                    (
+                        LABEL_NORMALIZED_SQL,
+                        truncate_label_value(sql_meta.normalized_sql),
+                    ),
                     (LABEL_IS_INTERNAL_SQL, sql_meta.is_internal_sql.to_string()),
                 ],
                 &[Utc::now()],
@@ -444,10 +447,13 @@ impl TopSqlSubResponseParser {
                 &[
                     (LABEL_NAME, METRIC_NAME_PLAN_META.to_owned()),
                     (LABEL_PLAN_DIGEST, hex::encode_upper(plan_meta.plan_digest)),
-                    (LABEL_NORMALIZED_PLAN, plan_meta.normalized_plan),
+                    (
+                        LABEL_NORMALIZED_PLAN,
+                        truncate_label_value(plan_meta.normalized_plan),
+                    ),
                     (
                         LABEL_ENCODED_NORMALIZED_PLAN,
-                        plan_meta.encoded_normalized_plan,
+                        truncate_label_value(plan_meta.encoded_normalized_plan),
                     ),
                 ],
                 &[Utc::now()],
diff --git a/src/sources/topsql_v2/upstream/parser.rs b/src/sources/topsql_v2/upstream/parser.rs
index 5db4f974..7fa10593 100644
--- a/src/sources/topsql_v2/upstream/parser.rs
+++ b/src/sources/topsql_v2/upstream/parser.rs
@@ -2,6 +2,21 @@ use std::sync::Arc;
 use vector_lib::event::LogEvent;
 
 use crate::sources::topsql_v2::schema_cache::SchemaCache;
+
+pub fn truncate_label_value(s: String) -> String {
+    // Truncate label value if it's too long, the default limit is 16KB in vminsert.
+    const MAX_LABEL_LEN: usize = 16384;
+    if s.len() > MAX_LABEL_LEN {
+        let mut idx = MAX_LABEL_LEN;
+        while idx != 0 && !s.is_char_boundary(idx) {
+            idx -= 1;
+        }
+        s[..idx].to_string()
+    } else {
+        s
+    }
+}
+
 pub trait UpstreamEventParser {
     type UpstreamEvent;
 
diff --git a/src/sources/topsql_v2/upstream/tidb/parser.rs b/src/sources/topsql_v2/upstream/tidb/parser.rs
index 50d1abac..b69df344 100644
--- a/src/sources/topsql_v2/upstream/tidb/parser.rs
+++ b/src/sources/topsql_v2/upstream/tidb/parser.rs
@@ -14,7 +14,7 @@ use crate::sources::topsql_v2::upstream::consts::{
     METRIC_NAME_TOTAL_RU, METRIC_NAME_EXEC_COUNT, METRIC_NAME_EXEC_DURATION,
     SOURCE_TABLE_TIDB_TOPSQL, SOURCE_TABLE_TOPSQL_PLAN_META, SOURCE_TABLE_TOPSQL_SQL_META, SOURCE_TABLE_TOPRU,
 };
-use crate::sources::topsql_v2::upstream::parser::UpstreamEventParser;
+use crate::sources::topsql_v2::upstream::parser::{truncate_label_value, UpstreamEventParser};
 use crate::sources::topsql_v2::upstream::tidb::proto::top_sql_sub_response::RespOneof;
 use crate::sources::topsql_v2::upstream::tidb::proto::{
     PlanMeta, SqlMeta, TopSqlRecord, TopSqlRecordItem, TopSqlSubResponse,
@@ -287,7 +287,10 @@ impl TopSqlSubResponseParser {
 
         log.insert(LABEL_SOURCE_TABLE, SOURCE_TABLE_TOPSQL_SQL_META);
         log.insert(LABEL_SQL_DIGEST, sql_digest);
-        log.insert(LABEL_NORMALIZED_SQL, sql_meta.normalized_sql);
+        log.insert(
+            LABEL_NORMALIZED_SQL,
+            truncate_label_value(sql_meta.normalized_sql.clone()),
+        );
         let now = Utc::now();
         log.insert(LABEL_TIMESTAMPS, LogValue::from(now.timestamp()));
         let date_str = now.format("%Y-%m-%d").to_string();
@@ -299,15 +302,19 @@ impl TopSqlSubResponseParser {
     fn parse_tidb_plan_meta(plan_meta: PlanMeta) -> Vec<LogEvent> {
         let mut events = vec![];
         let plan_digest = hex::encode_upper(plan_meta.plan_digest);
-        let encoded_normalized_plan =
-        hex::encode_upper(plan_meta.encoded_normalized_plan);
+        let encoded_normalized_plan = truncate_label_value(hex::encode_upper(
+            plan_meta.encoded_normalized_plan,
+        ));
         let mut event = Event::Log(LogEvent::default());
         let log = event.as_mut_log();
 
         // Add metadata with Vector prefix (ensure all fields have values)
         log.insert(LABEL_SOURCE_TABLE, SOURCE_TABLE_TOPSQL_PLAN_META);
         log.insert(LABEL_PLAN_DIGEST, plan_digest);
-        log.insert(LABEL_NORMALIZED_PLAN, plan_meta.normalized_plan);
+        log.insert(
+            LABEL_NORMALIZED_PLAN,
+            truncate_label_value(plan_meta.normalized_plan.clone()),
+        );
         log.insert(
             LABEL_ENCODED_NORMALIZED_PLAN,
             encoded_normalized_plan,