Where can I find the universal wheel in Zhoushan Lincheng?

You can go to some casters' physical stores to change them. If it's a regular model, it should be available, at least the one of the same height, and it should be usable. Still online, casters are sold in online stores, and there are many models and specifications. You can search online and have a look. If you don't know what kind of universal wheel you match, you can also contact the seller in the online store, and the seller will give you guidance.