What if the patent agent loses his diploma? Prepare what?

This is really troublesome for you. It's troublesome to lose your diploma, and you can't make it up. Do you still have an electronic version of your card? If there is, at least you can report it through the internet and then confirm it on the spot. You should go to the school to get a certificate, and make sure that your diploma information can still be found on the website of Xue Xin, and then talk to the patent office of the local intellectual property office. If they are willing to check online, you can report it. I'm going to register in May and June next year, and now I'm not sure if they will agree.