What should I do if I need to go back to China to transfer to Singapore and get a 30-day white card?

You can go back to China with a white card and passport, and the white card will be accepted by the customs. A piece of A4 paper.

Which school did you transfer to? If you haven't applied yet, you need to apply with a new passport. When you change a new family photo, your family photo number is also different. It was the first time to get a student's IPA when I entered the country. It's also A4 paper, called IPA. You can ask the flight attendant for a white card on the new plane and fill it out on the plane. Your student ID number will remain unchanged, Finn.

No one will be with you forever.

White cards need to be printed, and you can't apply in other schools. You can't apply for a student ID card in Singapore.

According to what you said,

If your student ID card is cancelled, the Immigration and Checkpoint Bureau will issue you a 30-day short-term residence permit (commonly known as a white card), which means that you can stay in China (Singapore) for 30 days, and you must return to China before the deadline, and generally it will not be extended. White card allows you to stay in our country for a short time, not for an entry visa. To return to China, if a netizen applies for a course, it must be approved by the Immigration and Checkpoint Bureau, notified by the school, have an IPA letter, or apply for entry.

Visa can enter our country.