A switch module applied for a power supply system is disclosed. The switch module comprises a power switch, an insulating member, a surge absorber and a pyrocondensation belt. The power switch is connected with the power supply system, the insulating member is set on the power switch, the surge absorber is electrically connected with the power switch and adjacent to the power switch, the pyrocondensation belt is connected with the surge absorber and the insulating member. The pyrocondensation belt shrinks with a temperature of the surge absorber. When the insulating member is in the initial state, the insulating member does not affect the power switch. The insulating member makes the power switch off when the shrinkage degree of the pyrocondensation belt develops enough to block the power switch from being on.