The invention discloses a multi-stage combined interlocking protection method of harbor shore power. The multi-stage combined interlocking protection method comprises the steps of 1, performing device-level protection configuration on a harbor shore power system, wherein the device-level protection configuration comprises the steps of configuring harbor shore power system device-level mechanical protection in each device-level equipment of the harbor shore power system, configuring harbor shore power system device-level instantaneous protection in each device-level equipment of the harbor shore power system and configuring harbor shore power system device-level delayed protection in each device-level equipment of the harbor shore power system; 2, performing system-level protection configuration on the harbor shore power system; and 3, monitoring the harbor shore power system in real time by the device-level protection and the system-level protection, and performing corresponding action according to the monitored data. On the basis of a multi-layer fault prevention and processing mechanism, the integral running of the harbor shore power system is protected more perfectly, and the running safety, the reliability and the integral utilization ratio of a ship shore system are guaranteed.