This paper first constructs the model of competitive intelligence service alliance based on cloud service platform. On that basis,the paper focuses on constructing and improving the internal operating mechanism of the alliance in order to ensure the orderly operation of alliance. The paper expounds on the dynamic mechanism,choice of alliance members and trust mechanism, coordination mechanism and risk management mechanism. First of all, the paper thoroughly analyzes the general relationship among the four operating mechanisms. Then, the paper clarifies the role of each operating mechanism in the service alliance in order to strengthen the contacts of members in the alliance, arouse the initiatives of the alliance member,promote information resources sharing, and meet the demands of competitive intelligence in manufacturing enterprises.