1. The high school is still there. You can take your ID card and diploma to the student registration department of the high school to reissue it. Most high schools can supplement materials such as graduate registration form/student registration form. If you have graduated from high school for many years and the school has not heard from you, then ask the school to open a certificate of studying (you must indicate your personal information, graduation time, official seal of the school, and the qualified education bureau to verify and stamp).

2. If the high school is merged or closed down, you should bring your diploma and other supporting materials to the local education bureau to inquire about the year-end book and produce relevant certificates.