The invention discloses an anti-surge circuit comprising a high-power resistor R1, an MOS tube Q1, a resistor R2, a resistor R3, a resistor R4, a voltage-regulator tube ZD1, a capacitor C1, an electrolytic capacitor EC1, a capacitor C3, a capacitor C2, a bridge pile BD1, and a fuse F1. The anti-surge circuit is characterized in that one end of the capacitor C1 is connected with the positive electrode of the electrolytic capacitor EC1, one end of the resistor R4 and the positive electrode of the bridge pile BD1; the other end of the capacitor C1, the negative electrode of the electrolytic capacitor EC1, the drain of the MOS tube Q1 and one end of the resistor R1 are grounded; the other end of the resistor R1 is connected with the negative electrode of the bridge pile BD1, the source of the MOS tube Q1, one end of the capacitor C2, the anode of the voltage-regulator tube ZD1, one end of the capacitor C3 and one end of the resistor R3; the other end of the capacitor C2 is connected with the gate of the MOS tube Q1, the cathode of the voltage-regulator tube ZD1 and one end of the resistor R2; and the other end of the resistor R2 is connected with the other end of the resistor R4, the other end of the resistor R3 and the other end of the capacitor C3. The surge current can be suppressed for both fast switching on/off and heat engine switching on/off, and therefore, the impact of electronic products to the power grid is reduced greatly.