diff --git a/headless/api/src/main/java/com/tencent/supersonic/headless/api/pojo/request/QueryMapReq.java b/headless/api/src/main/java/com/tencent/supersonic/headless/api/pojo/request/QueryMapReq.java
index 4eac5510a..4f0b166b9 100644
--- a/headless/api/src/main/java/com/tencent/supersonic/headless/api/pojo/request/QueryMapReq.java
+++ b/headless/api/src/main/java/com/tencent/supersonic/headless/api/pojo/request/QueryMapReq.java
@@ -14,7 +14,7 @@ public class QueryMapReq {
     private String queryText;
     private List<String> dataSetNames;
     private User user;
-    private Integer topN = 10;
+    private Integer topN = 0;
     private MapModeEnum mapModeEnum = MapModeEnum.STRICT;
     private QueryDataType queryDataType = QueryDataType.ALL;
 }
diff --git a/headless/core/src/main/java/com/tencent/supersonic/headless/core/chat/mapper/BaseMapper.java b/headless/core/src/main/java/com/tencent/supersonic/headless/core/chat/mapper/BaseMapper.java
index be968ee4c..fe297c1e8 100644
--- a/headless/core/src/main/java/com/tencent/supersonic/headless/core/chat/mapper/BaseMapper.java
+++ b/headless/core/src/main/java/com/tencent/supersonic/headless/core/chat/mapper/BaseMapper.java
@@ -46,6 +46,7 @@ public abstract class BaseMapper implements SchemaMapper {
 
     private void filter(QueryContext queryContext) {
         filterByDataSetId(queryContext);
+        filterTermByDetectWordLen(queryContext);
         switch (queryContext.getQueryDataType()) {
             case TAG:
                 filterByQueryDataType(queryContext, element -> !(element.getIsTag() > 0));
@@ -79,6 +80,22 @@ public abstract class BaseMapper implements SchemaMapper {
         }
     }
 
+    private static void filterTermByDetectWordLen(QueryContext queryContext) {
+        Map<Long, List<SchemaElementMatch>> dataSetElementMatches =
+                queryContext.getMapInfo().getDataSetElementMatches();
+        for (Map.Entry<Long, List<SchemaElementMatch>> entry : dataSetElementMatches.entrySet()) {
+            List<SchemaElementMatch> value = entry.getValue();
+            if (!CollectionUtils.isEmpty(value)) {
+                value.removeIf(schemaElementMatch -> {
+                    if (!SchemaElementType.TERM.equals(schemaElementMatch.getElement().getType())) {
+                        return false;
+                    }
+                    return StringUtils.length(schemaElementMatch.getDetectWord()) <= 1;
+                });
+            }
+        }
+    }
+
     private static void filterByQueryDataType(QueryContext queryContext, Predicate<SchemaElement> needRemovePredicate) {
         queryContext.getMapInfo().getDataSetElementMatches().values().stream().forEach(
                 schemaElementMatches -> schemaElementMatches.removeIf(
diff --git a/headless/server/src/main/java/com/tencent/supersonic/headless/server/service/impl/MetaDiscoveryServiceImpl.java b/headless/server/src/main/java/com/tencent/supersonic/headless/server/service/impl/MetaDiscoveryServiceImpl.java
index 44fa1f201..d7cadcad5 100644
--- a/headless/server/src/main/java/com/tencent/supersonic/headless/server/service/impl/MetaDiscoveryServiceImpl.java
+++ b/headless/server/src/main/java/com/tencent/supersonic/headless/server/service/impl/MetaDiscoveryServiceImpl.java
@@ -119,7 +119,9 @@ public class MetaDiscoveryServiceImpl implements MetaDiscoveryService {
                                                                SchemaMapInfo mapInfo,
                                                                Map<Long, DataSetResp> dataSetMap) {
         Map<Long, List<SchemaElementMatch>> result = new HashMap<>();
-
+        if (0 == topN) {
+            return result;
+        }
         SemanticSchema semanticSchema = semanticService.getSemanticSchema();
         for (Map.Entry<Long, List<SchemaElementMatch>> entry : mapInfo.getDataSetElementMatches().entrySet()) {
             Long dataSetId = entry.getKey();