Change to F 180 days visa with 2 entires.

Hi, I'm Thai. I applied F 180 days visa with 1 entires in Thailand and now already in China.
I have a plan to go to Hongkong next 2 week. It mean I need to apply for a new visa but I'm not sure what is better? between change my visa to be F 180 days 2 entires before go to Hongkong or I go to Hongkong and do the new F 180 days visa by using the same document ( JW202 form and admission letter from university)