Abstract: A tilt switch includes an insulating housing having a receiving chamber and a connecting cavity smaller than the receiving chamber in diameter to form a step therebetween, electrical terminals penetrating through the insulating housing to project into the connecting cavity, an insulating cover removably covered on the insulating housing, and a switching ball made of conductive materials and rollably placed between the insulating housing and the insulating cover. The step has a top face perpendicular to periphery surfaces of the connecting cavity and the receiving chamber. The switching ball needs to roll over the step having a hard span when the tilt switch changes working states between a closed state realized by the switching ball projecting into the connecting cavity to simultaneously connect with the electrical terminals, and an open state realized by tilting the tilt switch to disconnect the switching ball from at least one electrical terminal.