There are several reasons for the yellow light of student ticket checking:

1. The information on the student ticket does not match the information on the ID card, such as name, gender, etc.

2. The ID card has expired and has not been renewed.

3. The track information is damaged and cannot be read successfully.

4. The ID card is unsealed, damaged or defiled.

5. Identity cards involve counterfeiting, forgery and other illegal acts.

If the student ticket light is yellow, you can try to swipe your ID card again, or contact the staff at the local station for verification.