you need to renew your passport before applying for China visa, the passport with at least 6 months validity is required for China visa application. The requirements for business visa to China are:
one completed visa application form, one recent photograph for passport, passport valid up to at least six months with blank pages, the invitation letter from the China company, the original visa notice sheet from one authorized chinese governmental office, the China company can apply it for you.

an original notice of visa authorization from a duly authorized Chinese organization in China, namely, Ministries and Commissions of the State Council, the Government of all Provinces, Autonomous Regions, and Municipalities directly under the Central Government, and Foreign Affairs Offices and Bureaus of Economy and Commerce thereunder, and departments and units recognized by the Department of Consular Affairs of the Ministry of Foreign Affairs of the People’s Republic of China, with a multiple entry visa notification may apply for multiple entry visas.