As the last line of defense of the micro-grid system, emergency control can maintain the frequency stability after the system is greatly disturbed, which is of great significance to the stable operation of the micro-grid. This paper analyzes the problem that frequency emergency control strategy and round load shedding strategy are difficult to set and cannot accurately load down in micro-grid, and an independent micro-grid emergency control strategy based on the PCS output power limit criterion is proposed. When the external disturbance causes the PCS output power to exceed the limit, the PCS's over-limit power is calculated by taking into account the SOC equalization control strategy, the load is accurately cut off by the load accurate load shedding scheme, and adopting GOOSE communication technology for engineering implementation, proposing small step trend variation sampling algorithm and anti-point large number strategy to improve the response speed of control system, improving the stability of large-capacity independent micro-grid operation. The feasibility and effectiveness of this scheme are verified by an independent micro-grid project in Xinjiang.