The invention discloses a method for detecting faults of a heating switch circuit. The method includes: power on, namely controlling upper bridges and lower bridges to be disconnected; current detecting; namely if the current is not zero, judging that the upper bridges are damaged, judging short circuit of the upper bridges and the lower bridges by detecting currents of the lower bridges, or otherwise controlling the upper bridges to be disconnected while the lower bridges to connected; current detecting, namely, if the current is not zero, judging that the short circuit of the upper bridges is damaged, judging fault of the upper bridges and the lower bridges by detecting the current of the lower bridge, or otherwise, controlling the upper bridge and the lower bridge to be connected; current detecting, namely, if the current is zero, judging open-circuit fault of the upper bridges or open-circuit fault of all the lower bridges, or otherwise, judging the upper bridges to be normal, and judging open-circuit or short-circuit fault of the lower bridges by detecting the current of the lower bridges. When one switching tube fails and in short circuit and a heating element corresponding to the branch can still operate normally, the fault of switches can be detected and replaced through the fault detecting method.