Surge protection circuit

The utility model discloses a surge protection circuit, and the circuit comprises a first voltage-dividing circuit composed of a resistor and a capacitor. The circuit also comprises a rectification circuit for the rectification of the commercial power, and a control circuit for surge protection. The control circuit comprises a first comparator. The input end of the first voltage-dividing circuit is connected with the output end of the rectification circuit, and the output end of the first voltage-dividing circuit is connected with a first input end of the first comparator. A second input end of the first comparator is connected with a preset first standard power supply. Moreover, when the voltage of the commercial power is less than a first preset value, the voltage of the output end of the first voltage-dividing circuit is less than the voltage of the first standard power supply. The control circuit carries out surge protection and control according to the condition of an electric level outputted by the output end of the first comparator. The circuit improves the safety of power supply.