Where are you studying? You should probably grab a spot on an excavation every single summer. If you're not going somewhere with a professor who excavates in China, find one quick, grab your field school there, and impress them--be curious & helpful and make yourself the best candidate for a minimum-wage excavation assistantship. Not sure about the laws there, but at least in Greece foreigners are only allowed to oversee/screen/paperwork/lab + survey; countries really highly prefer to hire/train nationals. At the very least, you will have to be very competent with the language(s).
The only field school listed by the AIA & Shovelbums is at a Neolithic site in Xi'an (
http://archaeological.org/fieldwork/afob/7107), but that doesn't mean it's the only one. (Also, their maps are fucked up.) Just look around. Mongolia seems more active--I know the Smithsonian & Simon Fraser have been doing work there--so if China doesn't work out, that might be a good alternative.