The warning time is six months. According to the relevant information of Xi University of Technology, the lifting time of warning punishment is 6 months. The specific revocation method is:

1. When it comes to punishment, you can write a cancellation application in good faith.

2. Submit the counselor's signature, then go to the dean's signature and fill out the form after signing.

3. After filling out the form, sign and seal it in the courtyard, and there will be a cancellation notice after the formalities are completed.