need longer China visa with multi entry. I am Thai. My husband is German and has a Recidence Permit

You can try to apply for 1 year multiple entry visa with 90 days or 180 days in Thailand, but the final decision is up to visa officer, you can provide all your previous China visas to prove that you really need a multiple entry visa. The marriage certificate, the copy of your husband's passport, residence permit and work permit are also required.

In fact, you can apply for a Z visa as dependent of your husband who works in China, once you obtain Z visa, you can change it into a residence permit within 30 days after entering China, the permit can be used as a multiple entry visa.