diff --git a/docker/.env.example b/docker/.env.example
index 2b296e8066..05f7aba9bd 100644
--- a/docker/.env.example
+++ b/docker/.env.example
@@ -926,3 +926,5 @@ CREATE_TIDB_SERVICE_JOB_ENABLED=false
 # Maximum number of submitted thread count in a ThreadPool for parallel node execution
 MAX_SUBMIT_COUNT=100
 
+# The maximum number of top-k value for RAG.
+TOP_K_MAX_VALUE=10
diff --git a/docker/docker-compose.yaml b/docker/docker-compose.yaml
index dd72efc572..922e42fec5 100644
--- a/docker/docker-compose.yaml
+++ b/docker/docker-compose.yaml
@@ -386,6 +386,7 @@ x-shared-env: &shared-api-worker-env
   CSP_WHITELIST: ${CSP_WHITELIST:-}
   CREATE_TIDB_SERVICE_JOB_ENABLED: ${CREATE_TIDB_SERVICE_JOB_ENABLED:-false}
   MAX_SUBMIT_COUNT: ${MAX_SUBMIT_COUNT:-100}
+  TOP_K_MAX_VALUE: ${TOP_K_MAX_VALUE:-10}
 
 services:
   # API service