[Fluffagrams]

I've come across similar behaviours before although not quite to that extreme. It may be that he just needs a little time to adjust to his new surroundings and will settle down and start to explore his new home with a bit of encouragement.

What kind of cage is he living in? I've found that some of my shyer Chinese have preferred a more enclosed cage such as a bin cage with a more semi-transparent plastic than a traditional wire cage or a tank.
It's also worth mentioning that I have known them to become terrified in a cage that they're finding to be a little too large as well. My oldest Chinese was always lovely and tame but in a cage too large, he was terrified of every sound and sometimes it looked like even catching glimpse of his own shadow would send him darting for cover but yet he was fine out of his cage. Sometimes these problems can be overcome with the provision of lots of hides, levels and things like hammocks to reduce how exposed they feel but in other cases, as it was with my James, they may require something with a little less space.