The utility model belongs to a sound signal device, which is suitable for traffic tools using an air horn as the sound signal, such as automobiles, tractors, etc. The utility model comprises two large parts of an electric magnet and an air-passage switch. The utility model utilizes the electromagnetic force of the electric magnet as the power to attract the valve slice of a movable valve. Thus, the position of the valve slice of the valve can be changed, the air passage can be communicated, and thus, the air horn can generate the sound signal. The utility model is used, air passage pipes in the driver's cab can be reduced, and the electromagnetic internal attraction air horn switch device is convenient to maintain and install other parts; a horn button can be arranged on the optimal operating area for hands, which is convenient and labor-saving for use; the electromagnetic internal attraction air horn switch device can avoid the sound signal caused by habit actions sounding by mistake.