Three-phase overvoltage detection and protection device

The utility model provides a three-phase overvoltage detection and protection device, comprising a power supply input unit, an overvoltage detection circuit and a power supply switch unit, wherein three-phase alternating-current supplies of the power supply input unit are respectively connected with three commutation diodes; when the three-phase alternating-current supplies have overvoltage phenomenon, overvoltage signals are transmitted to the overvoltage detection circuit through the diodes, and high level is output to the power supply switch unit so as to lead a controllable silicon in the power supply switch unit to be triggered and communicated and lead a DCT electromagnet connected with the controllable silicon to be communicated, thus realizing leakage switch releasing. The product can detect the three-phase overvoltage and effectively prevent the situation that electrical equipment are damaged due to three-phase overvoltage, and has simple structure, good performance and low cost.