The invention discloses a switchgear detector. The detector comprises a controller, the controller is connected with a switch isolated control module and a digital-analog conversion unit, the digital-analog conversion unit is connected with eight signal detection conditioning units, and the digital-analog conversion unit comprises a microprocessor and an A/D conversion module and a D/A conversion module connected with the microprocessor. The switchgear detector can be used to overcome the defect that a present switchgear cannot monitor the work state thereof in real time. The detector can measure the three phases of voltages, the three phase of currents, the temperature and the humidity in the switchgear in real time to determine the state in the switchgear, and determines corresponding concrete operations; and when a fault occurs, power supply can be rapidly cut off, alarming is raised, the trouble of regular manual detection is avoided, and the problem that power supply is hard to cut off timely when the fault occurs and causes more loss is solved.