Can I get off at a different stop than what my ticket says?

So I'm planning to go to Quanzhou from Shanghai, but all the tickets on the day I want are sold out. However, I've noticed that there's still a lot of tickets for Shanghai-Xiamen on the same train I want. Could I buy a ticket that says from Shanghai to Xiamen, but get off at Quanzhou? Do they check tickets when you disembark on high-speed trains?