Food safety supervision should be made of three parts，internal supervision of production，coordinated supervision between enterprises，and external supervision of livestock supply chain. In this paper，the operating mechanism of livestock quality control system is a joint mechanism，including decision mechanism of livestock producing parties and constraint mechanism of government and social forces. By upgrading livestock production coordination mechanism to improve self-supervision of the enterprises，promoting comprehensive ability of slaughtering and processing enterprises to make internal supervision perfect，advancing information sharing to better off external supervision of supply chain，the mechanism will be improved.