A method for suppressing a narrow pulse is provided. The method is applied to a bridge switch circuit having at least one bridge arm which has an upper switch transistor and a lower switch transistor, and includes: detecting whether an original comparison value of a modulated wave in a current cycle is in a preset narrow pulse interval of the upper switch transistor, and if so, determining an adjustment interval of the upper switch transistor to which the original comparison value of the modulated wave currently pertains; and adjusting the original comparison value of the modulated wave to an adjusted comparison value of the modulated wave corresponding to the adjustment interval of the upper switch transistor to which the original comparison value of the modulated wave currently pertains according to a corresponding relationship between adjustment intervals of the upper switch transistor and adjusted comparison values of the modulated wave.