A circuit for detecting failure of an insulated-gate bipolar transistor (IGBT) power module, is provided to combine failure detecting signals of an IGBT power module using a photo coupler to transmit the isolated signals. The failure detecting circuit includes a circuit that combines six phase isolated failure detecting signals transmitted from a gate drive IC via a photo coupler to be one signal. A plurality of logic gate ICs are omitted, to reduce a material cost, a size of a circuit board, and power consumption.