The invention provides an overheat protection device. The overheat protection device comprises a thermal deformation part, a deformation sensor, a deformation actuator, a dynamic contact and a static contact, wherein the static contact is connected with a null line or a hot wire of a main circuit; the dynamic contact is connected with the null line or the hot wire of the main circuit and is in contact connection with the static contact; the thermal deformation part in thermal deformation triggers the deformation actuator, the deformation actuator pushes the deformation sensor to shift, and the deformation sensor drives the dynamic contact to move, so that the dynamic contact is disconnected from the static contact. By adopting the overheat protection device, when a heating assembly is overheated, the thermal deformation part becomes soft with heat, so that complex temperature field measurement for selecting a representative temperature position is not needed for the position of the thermal deformation part; and the soft thermal deformation part triggers the deformation actuator to push the deformation sensor to move, and the dynamic contact is disconnected from the static contact, so that the main circuit of an electric appliance is cut off, and the purpose of power-off protection is fulfilled.