diff --git a/inlong-sort-standalone/sort-standalone-source/src/main/java/org/apache/inlong/sort/standalone/source/sortsdk/FetchCallback.java b/inlong-sort-standalone/sort-standalone-source/src/main/java/org/apache/inlong/sort/standalone/source/sortsdk/FetchCallback.java
index 1d71caa6be6..edb4ddaacd5 100644
--- a/inlong-sort-standalone/sort-standalone-source/src/main/java/org/apache/inlong/sort/standalone/source/sortsdk/FetchCallback.java
+++ b/inlong-sort-standalone/sort-standalone-source/src/main/java/org/apache/inlong/sort/standalone/source/sortsdk/FetchCallback.java
@@ -113,7 +113,7 @@ public void onFinished(final MessageRecord messageRecord) {
                 context.reportToMetric(profileEvent, sortId, "-", SortSdkSourceContext.FetchResult.SUCCESS);
             }
 
-            client.ack(messageRecord.getMsgKey(), messageRecord.getMsgKey());
+            client.ack(messageRecord.getMsgKey(), messageRecord.getOffset());
         } catch (NullPointerException npe) {
             LOG.error("Got a null pointer exception for sortId " + sortId, npe);
             context.reportToMetric(null, sortId, "-", SortSdkSourceContext.FetchResult.FAILURE);