Protective circuit triggered by silicon controlled rectifier

The utility model discloses a protection circuit triggered by a silicon controlled rectifier, which comprises a silicon controlled rectifier driving circuit, a periodic signal driving circuit and an isolation capacitor CT2, and the isolation capacitor CT2 is arranged between the periodic signal driving circuit and the silicon controlled rectifier driving circuit. The silicon controlled rectifier driving circuit comprises a silicon controlled rectifier QR1 and a capacitor CR2, two ends of the silicon controlled rectifier QR1 and the capacitor CR2 are respectively connected with a power supply and a load, and a control end of the silicon controlled rectifier QR1 is connected with an isolation capacitor CT2; the periodic signal driving circuit comprises a main control chip, and input and output pins of the main control chip output periodic signals of high and low level periodic switching to pass through an isolation capacitor CT2 and drive a silicon controlled rectifier QR1, so that the influence of crash of the