Device and method for automatic alarming of power supply arrestor

The invention discloses a device and method for automatic alarming of a power supply arrestor, relating to the technical field of lightning protection of communication power supplies. The device comprises an over-voltage protection module, an alarm module and a dry node module which are capable of being sequentially connected between a connecting terminal N and a connecting terminal PE in parallel, wherein the dry node module can be connected to an NC/NO (Normally Closed/Normally opened) signal connecting terminal. The device and the method, disclosed by the invention, have the advantages that the arrestor can be protected, a fire accident due to misconnection of a firing line and a zero line of the arrestor is prevented from happening, the situation of the misconnection of the firing line and the zero line of the arrestor can be automatically identified and alarmed, the device is free of work and alarm when the firing wire and the zero line are connected correctly, the device is in a work state and can send out an alarm when the firing line and the zero line are misconnected, the current is extremely low and below 1mA when the device is in work and alarm, the device is energy-saving and environmental friendly, and the service life of a component is greatly prolonged.