The invention discloses a protective plug with outage trip and overvoltage trip functions. The protective plug comprises an amplifying circuit, a release, a rectifying circuit, a power light, a voltage reducing circuit, a silicon controlled rectifier, a zero sequence current transformer, a ground line current transformer and a phase loss protection circuit. The invention further provides a novel leakage protection device which has a phase loss protection function, an overvoltage protection function and a plug overtemperature protection function, wherein the phase loss protection function is to cut off the loaded power supply when the L or N-end power supply is interrupted or in poor contact; the overvoltage protection function is to cut off the loaded power supply by a power-up protector when the power supply voltage exceeds 280+/-10 V; the plug overtemperature protection function is to cut off the power supply when the plug temperature of the protector is up to the preset temperature.