China's economy is wholly dependent on our economy. The minute we stop importing from the Chinese, their economy will tank. The workers of China will revolt from loss of work, while the US will have a huge demand for increased production, creating huge job opportunities. Yes, stuff will get more expensive for a little while, but our economy will be easier to fix than theirs, since our demand for goods would increase demand for workers to produce the goods, while their surplus supply of workers will push wages down, skyrocket unemployment, and generally destroy their GDP. With that many unemployed workers, the country would likely collapse.
The only problem then will be the massive debt that we owe them. However, with more goods being generated nationally and more services moving that money around within our country, our GDP will jump significantly, and will most likely help pay off some of the debt. We can only hope that China won't look to World War III to "save" them from their own great depression at that time, especially given our extremely hostile economic tactics that would put them in that situation.