An auto anti-theft system with door-mount wireless remote-control pushbutton includes a main controller installed in a car for controlling the operation of the anti-theft system; a remote controller being carried by a user for code matching; and a small-size wireless remote-control pushbutton, which includes a coupling section for mounting the pushbutton to a car of any version or brand on or near a car door, such as on a door handle, a keyhole, a door surface, or a door window. The wireless remote-control pushbutton, the main controller, and the remote controller cooperate with one another to provide the functions of releasing and enabling the anti-theft system directly beside the car without pressing the remote controller button, making the anti-theft system a humanized design.