Can I transfer money to my home country? Is there a cap?

Yes, and there is a cap.

You may transfera maximum of $500 per daywith just your passport and valid visa.

To transfer more than $500 at one time, you will need to provide the following documents and information to the Chinese bank you are transferring money from:

• Original work contract, plus one copy

• A stamped income certificate provided by the employer's HR or finance department

• A stamped Individual Income Tax statement provided by the local tax bureau

• A copy of the passport ID page and visa page

• The name and headquarters address of the foreign bank you are transferring money to

• The foreign bank's SWIFT code or bank code for foreign wire transfers and the bank's routing number

• Your personal foreign bank account number

You may transfer up to the amount of your income as long as the documents prove you earned the amount through your employment.

Source: english.shanghai.gov.cn