diff --git a/flinkx-connectors/flinkx-connector-kafka/src/main/java/com/dtstack/flinkx/connector/kafka/converter/KafkaColumnConverter.java b/flinkx-connectors/flinkx-connector-kafka/src/main/java/com/dtstack/flinkx/connector/kafka/converter/KafkaColumnConverter.java
index f0c09cb130..c55630b886 100644
--- a/flinkx-connectors/flinkx-connector-kafka/src/main/java/com/dtstack/flinkx/connector/kafka/converter/KafkaColumnConverter.java
+++ b/flinkx-connectors/flinkx-connector-kafka/src/main/java/com/dtstack/flinkx/connector/kafka/converter/KafkaColumnConverter.java
@@ -183,7 +183,7 @@ public byte[] toExternal(RowData rowData, byte[] output) throws Exception {
             } else {
                 List<String> values = new ArrayList<>(row.getArity());
                 for (int i = 0; i < row.getArity(); i++) {
-                    values.add(row.getField(i).asString());
+                    values.add(row.getField(i) == null ? "" : row.getField(i).asString());
                 }
                 map = decode.decode(String.join(",", values));
             }