The invention relates to a surge protector, which mainly includes a breaking switch, a tripping mechanism, an inertial device (inertial wheel), a buffer displacement shrapnel, an electromagnet, a bimetallic sheet, a lightning protection element and upper and lower terminals. The upper terminal is connected in series with the breaking switch, electromagnet, lightning protection element and lower terminal; the electromagnet can drive the tripping mechanism to move, and the tripping mechanism is equipped with a buffer displacement shrapnel and an inertial device (inertial wheel) to ensure that when The electromagnet push rod will only act when it continues to move, and the electromagnet push rod will recover when the lightning current passes through the instant, and the tripping mechanism will not act to ensure that the breaking switch breaks the SPD fault path correctly; the temperature of the lightning protection component is transmitted through the heat conduction patch. As for the bimetal strip, when the temperature is too high, the bimetal strip can deform and drive the tripping mechanism to move and break the circuit. This invention has a comprehensive lightning protection function, realizes quick breaking of power frequency short-circuit current, trips when leakage current is too large, smooth discharge of lightning current, convenient installation, safety and effectiveness.