The invention discloses an electronic whistle horn control circuit with over-voltage suppression for vehicles and a suppression method. Whistle horns of ordinary vehicles do not adopt over-voltage suppression, and when the power supply voltage of the horn exceeds a certain value, the horn cannot be well protected after over-voltage, and the service life of the horn can be reduced. The electronic whistle horn control circuit with over-voltage suppression for the vehicles consists of a controller (1), a drive circuit (2), a horn system (3) and an over-voltage suppression circuit (4), wherein the controller is separately connected with the drive circuit and the over-voltage suppression circuit, the drive circuit is connected with the horn system, the controller and the over-voltage suppression circuit form a system with closed-loop feedback, and the system with closed-loop feedback completes a control loop of an electric horn for the vehicle. The electronic whistle horn control circuit and the suppression method disclosed by the invention are applied to the electronic whistle horns.