1. Can the ID number be changed on a real-name train ticket?

Answer: No!

Changing train tickets can only change the time, but not other things!

This is stipulated in the "Railway Passenger Transport Regulations".

2. Can I use another ID card to buy after the refund?

Answer: In theory it is possible, but in practice it is very difficult.

The refund window is only responsible for refunding tickets and does not handle ticket sales. The host cannot purchase tickets on the spot.

The refunded train ticket will be published online again. All online ticket outlets/windows can sell this ticket. As for which ticket outlet/window sells it, it depends on which ticket outlet/window. The staff is quick.

Supplementary answer:

Q: Can a take b’s ID card and train ticket to enter and exit the station?

Answer: No!

The train implements a real-name system. When entering the station to check in and take the train, the passenger, ID card, and ticket must be checked, and the three information must be unified.

Unless the appearance of a and b is extremely similar, so similar that it is difficult to distinguish based on photos alone, in this case, they can get away with it.