I want to travel abroad in the summer vacation, but the travel agency needs a school certificate. How to write the certificate?

There is no fixed format, because leaving the country involves many legal provisions, and the travel agency should bear a considerable part of legal responsibilities while serving you to prevent you from staying abroad. They ask for the school certificate you want to prove that you are indeed a student at school, or at least that you may return to China, instead of giving up your studies and working illegally abroad.

If you have already worked, they will also ask for your bank deposit or other work certificates.

If there is no fixed format, write the content to prove that you are a student at school, and then what major, grade, class teacher and department head sign it, and the school seals it.