Disclosed are a three-phase wiring detection device and a coincidence phase detection method. The three-phase wiring detection device and the coincidence phase detection method compare a power factor relationship between a three-phase voltage and a three-phase current, and determines whether a coincidence phase is coincident between the three-phase voltage and the three-phase current, thereby checking whether the coincidence phase is accurately coincident. Therefore, whether the coincidence phase is coincident between the three-phase voltage and the three-phase current can be checked, and a function of a reverse phase detector and a function of a coincidence phase checker can be implemented. Also, the three-phase voltage and the three-phase current can be accurately detected.