You need the below documents for China business visa application:
1. Application form:
2. Passport and One Passport photocopy.
3. One recent passport size photograph.
4. Visa notification issued by an authorized unit in China
or invitation letter from the legally registered company in China.
5. Covering letter from your company or office with the details of the visiting purpose.

if you read the above information on this page, you will know that you need to go to CVASC to apply for China visa rather than China embassy/consulate. The office hours and office day are listed above.