You can use Alipay to book student train tickets online. The method is as follows:

1. First, open the Alipay client and log in to your Alipay account.

2. Then on the Alipay homepage, click on the search bar, enter "ticket", and select "train tickets and air tickets" pointed by the red arrow in the list.

3. Next, on the page, enter the place you want to go, click "Student Ticket Query", and click "Start Search".

4. Next, select the required train number on the page and click to purchase tickets.