Ordinary cards can be swiped, but not overdrawn.

What can be overdrawn is a credit card ~ so what you have is not a credit card ~ and if you hand in your resident landing card (Korean) when you go back to the airport for security check, your account in Korea will be cancelled directly.

At the security window, the staff will ask you if you will return to Korea within the visa date.

If you really want to return to China and will not live in Korea for a long time (including studying abroad)

Don't be clever here. Be sure to tell the truth. If you don't come back, they will take back your resident ID card (Korean).

And those personal information about you will also be automatically deleted, such as bank account number and mobile phone (be sure to remind you to pay the mobile phone fee before you leave and cancel the business. Don't think that it doesn't matter if I don't pay it anyway, because if you don't, your personal information will have a bad record in Korea, which has nothing to do with your ID card (Korean). After this record exists, if you want to visit relatives, study or even immigrate to Korea, you will be refused a visa)