To add to another reply, the big perk of bitcoin mining is that you can launder your money through the purchase of equipment, real estate and power directly into US Dollars.
It's as that comment said, basically just a way to turn Renminbi into Dollars without the Chinese government knowing about it.
I don't know enough about Chinese politics to be able to reliably comment on their intentions, but buying dollars like this could help push down the price of the Renminbi compared to the Dollar. That has been part of China's economic policy for a long time. Also, when you think about how China is under international pressure to allow the Renminbi to start naturally moving up in value, these types of currency pressures would certainly make a nice way to keep the Renminbi low without having to responsibility for it.
This has been discussed many times before, however it's often in context to North America. You specifically have to look for articles that calculate economics of Chinese prices (electricity, building materials, labour, hardware etc) because they differ greatly depending on where you are.
I think it's economical right now, but ceases to be economical the second new hardware comes out and the difficulty goes up. So they have to pay for this pretty quickly.
It's as that comment said, basically just a way to turn Renminbi into Dollars without the Chinese government knowing about it.