The invention relates to a novel surge protection device. The novel surge protection device comprises a lightning protection element, an over-current protection device, a thermal protection device and a shell, wherein the lightning protection element and the over-current protection device are connected in series so as to form a surge discharge circuit. The thermal protection device is located on an electrode of the lightning protection element. The novel surge protection device further comprises a magnetic field detection device, a current limiter, a buffer displacement elastic sheet, an inertia device, an electromagnetic actuating mechanism, a linkage mechanism and a normally-open contact. The magnetic field detection device is installed near the surge discharge circuit and is connected with the electromagnetic actuating mechanism. The electromagnetic actuating mechanism controls the buffer displacement elastic sheet to move. The buffer displacement elastic sheet is connected with the inertia device. The inertia device controls the normally-open contact to act through the linkage mechanism. The normally-open contact and the current limiter are connected in series so as to form a bypass which is connected in parallel with two ends of the lightning protection element. With the novel surge protection device of the invention adopted, the problem of the actuating dead zones of an existing thermal protection device and an existing over-current protection device can be solved fundamentally.