I want to get my bedding sets designed in China with my own designs,  but I wanted to the protection Laws or what do I have to do to make sure they do not resale my designs to another company.

You need to consult a lawyer for this I think.
You can form a contract with the company asserting your ownership over the designs 'intellectually' and have some provisions preventing them from dissemination thereof, but if you think about it, anyone could copy your designs.

This is why there is so much TM infringements on sports attire and kits. The Football clubs don't exactly want all of their merchandise and designs to be copied even where the providers will say 'Not official', but it still happens. (Although obviously wrong).

If someone wants to copy something then its going to happen.

I think you are maybe overthinking things though when all it is is bedding designs?
Regards.