The utility model provides a detection and verification device of a transformer partial discharge and positioning monitoring assembly. The detection and verification device comprises a power supply, an isolation filtering transformer, a non-partial-discharge boosting transformer, a voltage divider, a sample Cx, a digital partial discharge instrument, a UHF sensor and a computer. By adopting the detection and verification system, a transformer partial discharge UHF on-line monitoring assembly and a partial discharge ultrasonic positioning/UHF positioning on-line monitoring assembly can be detected and verified, and meanwhile, the sensitivity and the positioning error of the on-line monitoring assemblies can be detected and verified. A developed UHF sensor installation tool can realize the detection of various types of UHF sensors; and through a developed electrode model, a typical partial discharge fault of a transformer can be simulated, and the detection and verification of the on-line monitoring intelligent assemblies on the monitoring sensitivity of various typical types of faults are carried out.