The maximum reduction of equipment risk is an effective way to prevent power grid accident. From the perspective of multiple factor analysis of equipment risk, considering impact of equipment importance and equipment hidden danger on equipment risk, equipment risk influence degree is defined, equipment importance indicators and equipment hidden danger indicators are proposed, and the index system of calculating equipment risk influence degree is established. On the basis of this system, the equipment relative importance matrix and equipment relative hidden danger are used to establish the calculation model of equipment risk influence degree. The risk influence degree of each equipment is obtained to identify high risk equipment that has an important impact on reliable, stable and safe operation of power grid. Therefore, it is of great significance to focus on the high risk equipment to reduce the overall risk level of power system. Finally, the method is applied to calculate risk influence degree of equipment in 220 kV Donggou substation in Jincheng. Simulation results verify the effectiveness and feasibility of the proposed method, which provides data support for mining high risk equipment. This work is supported by National Natural Science Foundation of China (No. 51507063) and Science and Tehnology Project of Headquarters of State Grid Corporation of China (No. B34681150152).