Abstract: The tripping of shunt capacitor bank circuit during operation is a common situation in power system. Capacitor trip can be caused by a variety of reasons. Therefore, the actual analysis should be combined with the operating conditions of the capacitor when tripping, considering various influencing factors for comprehensive analysis. This paper analyzes the high tripping times of shunt capacitor banks in Chongqing Bishan Power Supply Company of State Grid in recent three years, and statistics the manufacturer of tripping capacitor banks, the running time of tripping capacitor, and the protection action of tripping capacitor. It is confirmed that the main reasons leading to capacitor tripping are three phase voltage unbalance caused by capacitor capacitance change, tripping caused by thunderstorm and system voltage fluctuation. In view of the abnormal tripping situation, the corresponding preventive measures are put forward, which can be used as reference for substation maintenance and maintenance personnel.