1. This may be a hit or a miss but: here
. There's a downloader for satellite view and street map view.
2. Google Earth (Pro, Plus) has a built-in cache to let you store some maps temporarily. You can try to find some programs or other methods to patch multiple cache files together.
3. A third option is to just buy a GPS system, so you'll know where you are while in China. You'd have to find one that offers the Chinese maps, of course.
4. A fourth, more ridiculous option is to take a ton of screenshots of Google Maps/Earth.
5. Google produced something called "Maemo Mapper" which is supposed to let you download maps from Google in pre-defined zoom levels. I'm not sure about any specifics, but Google should help you there. Try here.
A word of warning though: I was reading an article on China and how quickly it's growing. Your maps might be out-of-date or totally inaccurate in China, as experienced by some people who have GPS devices.