If it is to meet the children who do not need to buy tickets, you can follow directly into the station when you enter. The relevant regulations are that an adult can carry one child under 130cm for free, and more than one person can buy a full ticket. You can also bring your student card to buy half the ticket, you can also use the citizen card, student bus card electronic wallet.
If you need to buy a ticket, you can buy a subway ticket to ride, or buy a Hangzhou Pass card to ride the Hangzhou metro.