Portable overheat protective varistor

The invention discloses a portable overheat protective varistor. The varistor comprises a varistor base and an overheat protective packaged shell. The varistor base comprises a varistor ceramic body and end electrodes arranged at two ends of the varistor ceramic body. The overheat protective packaged shell comprises two electrode caps, an explosion-proof glass shell, a connection line electrode, an insulating gasket, and two spiral springs. One end of the connection line electrode is tightly connected with the inner bottom of one electrode cap through high-temperature tin soldering, and the other end thereof is tightly connected with the end electrodes of the varistor base through low-temperature tin soldering. One end surface of the varistor base, one spring, the insulating gasket and theelectrode caps are connected into a whole. The two electrode caps are respectively connected with two ends of the explosion-proof glass shell tightly through threads. The other end surface of the varistor base and the other