I'm going to visit the children studying in America. Materials to be provided for visa: I-20 form, original or copy of the invitation letter from the school?

First of all, personal information: 1 Need a resume (focus on the purpose of going abroad clearly) 2 Need to go to the bank to open an asset certificate of about 4,5w, bring the original and sign it in person; 3 Salary certificate (original, printed on the paper of your work unit) or business license (copies are all original) 4 Real estate license or anything that can prove that you are rich. A copy will be fine. You must bring a receipt account with five passports and handling fees (all originals). 6. On-the-job certificate and leave certificate (bilingual). My recent passport photo, a relationship certificate: the invitation letter (original), a recent photo of you and your children, your recent email records with your children, and your plans after going abroad (roughly). These are necessary materials. If the invitation is sent by the school, if it is sent in the name of the child, I suggest you consider applying for a personal tourist visa. Nowadays, visas in the United States are easy to handle, and the relative review of tourism is not particularly complicated.