Abstract: In recent years, in the power system, the non-fault trip event of the circuit breaker has gradually increased due to the spring not storing energy storage, among which the spring energy storage methods used in different voltage levels are different, mainly including hydraulic spring energy storage and elastic mechanism spring energy storage. Spring energy storage provides power for the circuit breaker so that it can open and close normally, but due to some problems, the spring energy storage circuit will be affected, resulting in the spring unstored energy storage blocking circuit. There are two main design methods in the circuit breaker spring unstored locking circuit: one is split phase locking, and any phase spring is not stored to cause the phase closing circuit to be blocked, thereby blocking the three phases; The other is that the spring does not directly block the three phases without energy storage, both of which will cause the circuit breaker to be closed in place at a distance during the operation process, causing corresponding protection actions. Therefore, by introducing the accident caused by the three-phase spring not energy storage, and by comparing the circuit breakers of the same manufacturer in two different substations, this paper focuses on analyzing which reasons will cause the circuit breaker to lock the circuit due to the spring not storing energy.