diff --git a/cocoscreator_projects/scripts/test/ui-frames.test.mjs b/cocoscreator_projects/scripts/test/ui-frames.test.mjs
index 515862d..fd662d2 100644
--- a/cocoscreator_projects/scripts/test/ui-frames.test.mjs
+++ b/cocoscreator_projects/scripts/test/ui-frames.test.mjs
@@ -73,10 +73,17 @@ test('frameFileName 单帧图原样返回', () => {
 
 test('frameFileName undefined 作为 frameIndex 抛 RangeError', () => {
   assert.throws(() => frameFileName('00014.png', undefined, 12), RangeError);
+  assert.throws(() => frameFileName('00014.png', undefined, 12), /00014\.png/);
 });
 
 test('frameFileName NaN 作为 frameIndex 抛 RangeError', () => {
   assert.throws(() => frameFileName('00014.png', NaN, 12), RangeError);
+  assert.throws(() => frameFileName('00014.png', NaN, 12), /00014\.png/);
+});
+
+test('frameFileName 越界抛 RangeError 且带图名', () => {
+  assert.throws(() => frameFileName('00014.png', 13, 12), RangeError);
+  assert.throws(() => frameFileName('00014.png', 13, 12), /00014\.png/);
 });
 
 test('frameNames 返回全部帧，下标 0 对应帧 1', () => {
diff --git a/cocoscreator_projects/scripts/ui-migration/frames.mjs b/cocoscreator_projects/scripts/ui-migration/frames.mjs
index acf0a84..ffc4e12 100644
--- a/cocoscreator_projects/scripts/ui-migration/frames.mjs
+++ b/cocoscreator_projects/scripts/ui-migration/frames.mjs
@@ -29,9 +29,9 @@ export function padWidth(frameCount) {
 export function frameFileName(bmp, frameIndex, frameCount) {
   if (frameCount <= 1) return bmp;
   const normalized = frameIndex === 0 ? 1 : frameIndex;
-  if (!Number.isInteger(normalized) || normalized <= 0) {
+  if (!Number.isInteger(normalized) || normalized <= 0 || normalized > frameCount) {
     throw new RangeError(
-      `帧号非法: ${bmp} frameIndex=${frameIndex}（有效范围 >= 1，0 视同 1）`,
+      `帧号非法或越界: ${bmp} frameIndex=${frameIndex}（有效范围 1..${frameCount}，0 视同 1）`,
     );
   }
   const base = bmp.replace(/\.png$/i, '');