datangzhu Your export settings and texture packer settings seem to be fine. Could you please email us the exported files so we can see what is causing this?: contact@esotericsoftware.com
Please include the URL of this forum thread in the email so we know the context. Then we can take a look at what's wrong.

datangzhu Thank you for sending your Spine project files! It was quite a tricky problem to find, but the cause of this problem lies in the naming of some attachments in your skeleton.

Your skeleton has two attachments that contain the string ".png" in the attachment name: 010_body.png and 010_er.png.
These images have been renamed in the atlas text as 010_body or 010_er. In other words, the trailing .png has been removed. As a result, the error occurred during import because matching attachments could not be found.

To solve this problem, remove ".png" from the attachment names and repack the texture again. It should then import correctly.