diff --git a/flink-connector-mongodb-cdc/src/main/java/com/ververica/cdc/connectors/mongodb/source/reader/fetch/MongoDBFetchTaskContext.java b/flink-connector-mongodb-cdc/src/main/java/com/ververica/cdc/connectors/mongodb/source/reader/fetch/MongoDBFetchTaskContext.java
index f063c332e0..23d97c0c5f 100644
--- a/flink-connector-mongodb-cdc/src/main/java/com/ververica/cdc/connectors/mongodb/source/reader/fetch/MongoDBFetchTaskContext.java
+++ b/flink-connector-mongodb-cdc/src/main/java/com/ververica/cdc/connectors/mongodb/source/reader/fetch/MongoDBFetchTaskContext.java
@@ -132,7 +132,7 @@ public boolean isRecordBetween(SourceRecord record, Object[] splitStart, Object[
         BsonDocument splitKeys = (BsonDocument) splitStart[0];
         String firstKey = splitKeys.getFirstKey();
         BsonValue keyValue = documentKey.get(firstKey);
-        BsonValue lowerBound = ((BsonDocument) splitEnd[1]).get(firstKey);
+        BsonValue lowerBound = ((BsonDocument) splitStart[1]).get(firstKey);
         BsonValue upperBound = ((BsonDocument) splitEnd[1]).get(firstKey);
 
         // for all range