diff --git a/src/connector/src/sink/mod.rs b/src/connector/src/sink/mod.rs
index 0d47f777b4a5f..c7ed6c8449270 100644
--- a/src/connector/src/sink/mod.rs
+++ b/src/connector/src/sink/mod.rs
@@ -299,8 +299,10 @@ fn datum_to_json_object(field: &Field, datum: DatumRef<'_>) -> ArrayResult<Value
         (DataType::Decimal, ScalarRefImpl::Decimal(v)) => {
             json!(v.to_text())
         }
-        (DataType::Timestamptz, ScalarRefImpl::Timestamp(v)) => {
-            json!(v.0.and_local_timezone(chrono::Utc).unwrap().to_rfc3339())
+        (DataType::Timestamptz, ScalarRefImpl::Int64(v)) => {
+            // risingwave's timestamp with timezone is stored in UTC and does not maintain the
+            // timezone info and the time is in microsecond.
+            json!(v)
         }
         (DataType::Time, ScalarRefImpl::Time(v)) => {
             // todo: just ignore the nanos part to avoid leap second complex
@@ -341,11 +343,10 @@ fn datum_to_json_object(field: &Field, datum: DatumRef<'_>) -> ArrayResult<Value
             }
             json!(map)
         }
-        _ => {
-            return Err(ArrayError::internal(format!(
-                "datum_to_json_object: unsupported data type {:?}, {:?}",
-                field.data_type, scalar_ref,
-            )));
+        (data_type, scalar_ref) => {
+            return Err(ArrayError::internal(
+                format!("datum_to_json_object: unsupported data type: field name: {:?}, logical type: {:?}, physical type: {:?}", field.name, data_type, scalar_ref),
+            ));
         }
     };
 
@@ -356,6 +357,7 @@ fn datum_to_json_object(field: &Field, datum: DatumRef<'_>) -> ArrayResult<Value
 mod tests {
 
     use risingwave_common::types::{Interval, ScalarImpl, Time, Timestamp};
+    use risingwave_expr::vector_op::cast::str_with_time_zone_to_timestamptz;
 
     use super::*;
     #[test]
@@ -401,23 +403,15 @@ mod tests {
 
         // https://github.com/debezium/debezium/blob/main/debezium-core/src/main/java/io/debezium/time/ZonedTimestamp.java
         let tstz_str = "2018-01-26T18:30:09.453Z";
-        let tstz_value = datum_to_json_object(
+        let tstz_inner = str_with_time_zone_to_timestamptz(tstz_str).unwrap();
+        datum_to_json_object(
             &Field {
                 data_type: DataType::Timestamptz,
                 ..mock_field.clone()
             },
-            Some(
-                ScalarImpl::Timestamp(
-                    chrono::DateTime::parse_from_rfc3339(tstz_str)
-                        .unwrap()
-                        .naive_utc()
-                        .into(),
-                )
-                .as_scalar_ref_impl(),
-            ),
+            Some(ScalarImpl::Int64(tstz_inner).as_scalar_ref_impl()),
         )
         .unwrap();
-        chrono::DateTime::parse_from_rfc3339(tstz_value.as_str().unwrap_or_default()).unwrap();
 
         let ts_value = datum_to_json_object(
             &Field {