The specific operation steps of setting personalized signature under the cover of WeChat are as follows:

1. First open WeChat and click "My avatar" to enter.

2. Then click the "More" option on this page.

3. Then click the "Personalized Signature" option on this page.

4. Then set a personalized signature on this page and click the "Save" option in the upper right corner.

5. Finally, you can see it by opening the circle of friends.