diff --git a/paimon-lance/src/main/java/org/apache/paimon/format/lance/LanceFileFormat.java b/paimon-lance/src/main/java/org/apache/paimon/format/lance/LanceFileFormat.java
index 05005432b6d8..2eee2639b7f2 100644
--- a/paimon-lance/src/main/java/org/apache/paimon/format/lance/LanceFileFormat.java
+++ b/paimon-lance/src/main/java/org/apache/paimon/format/lance/LanceFileFormat.java
@@ -180,12 +180,13 @@ public Void visit(LocalZonedTimestampType localZonedTimestampType) {
 
         @Override
         public Void visit(VariantType variantType) {
-            return null;
+            throw new UnsupportedOperationException(
+                    "Lance file format does not support type VARIANT");
         }
 
         @Override
         public Void visit(BlobType blobType) {
-            return null;
+            throw new UnsupportedOperationException("Lance file format does not support type BLOB");
         }
 
         @Override
diff --git a/paimon-lance/src/test/java/org/apache/paimon/format/lance/LanceFileFormatTest.java b/paimon-lance/src/test/java/org/apache/paimon/format/lance/LanceFileFormatTest.java
index 2352be764f91..9a7152e25944 100644
--- a/paimon-lance/src/test/java/org/apache/paimon/format/lance/LanceFileFormatTest.java
+++ b/paimon-lance/src/test/java/org/apache/paimon/format/lance/LanceFileFormatTest.java
@@ -101,4 +101,20 @@ public void testValidateDataFields_SupportedTypes() {
         // Validate that no exception is thrown for supported types
         assertDoesNotThrow(() -> format.validateDataFields(rowType));
     }
+
+    @Test
+    public void testValidateDataFields_UnsupportedVariantType() {
+        LanceFileFormat format =
+                new LanceFileFormat(new FileFormatFactory.FormatContext(new Options(), 1024, 1024));
+        RowType rowType = RowType.of(DataTypes.VARIANT());
+        assertThrows(UnsupportedOperationException.class, () -> format.validateDataFields(rowType));
+    }
+
+    @Test
+    public void testValidateDataFields_UnsupportedBlobType() {
+        LanceFileFormat format =
+                new LanceFileFormat(new FileFormatFactory.FormatContext(new Options(), 1024, 1024));
+        RowType rowType = RowType.of(DataTypes.BLOB());
+        assertThrows(UnsupportedOperationException.class, () -> format.validateDataFields(rowType));
+    }
 }