CALEA intercepts are implemented through automated systems, the judge signs a warrant, it's entered into a computer and the wiretaps are done automatically, with the traffic routed to the requesting agency's systems.
In China, they probably noticed that they don't have a legal intercept facility built in, and don't want to spend the time to negotiate with all of the interested parties. So, they put a person on site.
The threat and the outcome is the same. If you don't provide legal intercept, you're going to get locked up.
For an example of what level of access these systems provide, a Greek carrier was hacked through theirs - the hacker(s) turned it on and used it to listen in on the Prime Minister's phone calls[1].
I'm not saying that the Chinese are doing the right thing, just that it's largely equivalent to what happens here.
[1] http://spectrum.ieee.org/telecom/security/the-athens-affair
[2] https://en.wikipedia.org/wiki/Communications_Assistance_for_...
I expect that the intent is different, although I don't know US law. The Chinese intent is to (forcibly?) prevent unwanted communication. I doubt that is the intent of the US law.