Abstract: Considering the maturity of the technology and the reliability and safety of the equipment itself, in general, the energy storage mode of the circuit breakers in substations is spring energy storage mode, and the phase-separated spring energy storage mechanism is mostly used in the circuit breakers of 220 kv and above, it mainly considers that single-phase transient fault does not affect the normal operation of the other two phases in the system with large current grounding, and that non-full-phase protection and three-phase inconsistent protection are normally arranged in the circuit breaker protection of the phase-separation mechanism, when the circuit breaker can not run at the same time because of some reason, such as abnormal closing circuit before power supply, unstored energy of closing spring and so on, the protection will start the outlet to maintain the system stability. In this paper, the analysis of a 220 kv circuit breaker three-phase inconsistent protection action event caused by a closing spring not energy-stored power supply, exposure problems and preventive measures, to provide reference and thinking for substation operation and maintenance personnel, avoid repeating events.