diff --git a/src/storage/blocksstable/index_block/ob_index_block_aggregator.cpp b/src/storage/blocksstable/index_block/ob_index_block_aggregator.cpp
index 101af65528..03ca468b29 100644
--- a/src/storage/blocksstable/index_block/ob_index_block_aggregator.cpp
+++ b/src/storage/blocksstable/index_block/ob_index_block_aggregator.cpp
@@ -49,6 +49,7 @@ int ObColNullCountAggregator::init(const ObColDesc &col_desc, ObStorageDatum &re
     if (is_skip_index_black_list_type(col_desc.col_type_.get_type())) {
       set_not_aggregate();
     }
+    col_desc_ = col_desc;
   }
   return ret;
 }
@@ -73,6 +74,9 @@ int ObColNullCountAggregator::eval(const ObStorageDatum &datum, const bool is_da
     // Skip
   } else if (is_data) {
     null_count_ += datum.is_null() ? 1 : 0;
+  } else if (datum.is_null()) {
+    ret = OB_ERR_UNEXPECTED;
+    LOG_WARN("Unexpected index block data", K(ret), K(datum));
   } else {
     null_count_ += datum.get_int();
   }
diff --git a/src/storage/blocksstable/index_block/ob_index_block_util.h b/src/storage/blocksstable/index_block/ob_index_block_util.h
index 5f49e52a41..2f72492b2a 100644
--- a/src/storage/blocksstable/index_block/ob_index_block_util.h
+++ b/src/storage/blocksstable/index_block/ob_index_block_util.h
@@ -156,14 +156,14 @@ OB_INLINE static int get_skip_index_store_upper_size(
 
 OB_INLINE static bool is_skip_index_black_list_type(const ObObjType &obj_type)
 {
-  return ob_is_json_tc(obj_type) || ob_is_geometry_tc(obj_type)
+  return ObNullType == obj_type || ob_is_json_tc(obj_type) || ob_is_geometry_tc(obj_type)
       || ob_is_user_defined_sql_type(obj_type);
 }
 
 OB_INLINE static bool is_skip_index_while_list_type(const ObObjType &obj_type)
 {
   const ObObjTypeClass tc = ob_obj_type_class(obj_type);
-  return (ObNullTC <= tc && tc <= ObLobTC) || ObDecimalIntTC == tc;
+  return (ObIntTC <= tc && tc <= ObLobTC) || ObDecimalIntTC == tc;
 }
 
 } // blocksstable