See if you can dig out the e-book “Flying Upside Down”... It’s a pretty accurate description of flying in China, (written by a former disgruntled expat pilot)

My current rotation is 3 weeks on/ 3 weeks off. It can br brutal. As was mentioned earlier, time limitation are 40 hours a week, 100 a month. 36 hours consecutive rest required per rolling seven day period. Means I normally work 5 on, 1 off or so.

And pay attention to things that are not in the contracts. For example, vacation rules are not in the contracts that the agencies release. While I am on a 3/3 rotation, I can not take more than 15 days in Jan/Feb or July/Aug... and have to arrange my schedule so that I rotate every year Christmas home or in China. My advice, if you are considering it, get a relationship with someone at the particular airline you are looking at. They can give you the ins and outs and the gotchas at their airline.

It is a different world and takes effort to make it.