The invention provides a detection device for testing the working state of a substation SF6 sensor. The detection device comprises a gas storage mechanism for storing an SF6 gas and an SF6 sensor detection mechanism; a detection gas hood is provided with a gas inlet, the gas storage mechanism is provided a gas outlet, the gas outlet is provided with a control valve for controlling the output of the SF6 gas in the gas storage mechanism, and the output end of the control valve is connected with the gas inlet of the detection gas hood through a conduit; a test plate is arranged in the gas hood ofthe detection gas hood, and a display screen and a handle are arranged on the external surface of the detection gas hood; the display screen and the SF6 sensing tester are respectively connected withthe controller; and the controller obtains the concentration information of the SF6 gas in the gas hood through the SF6 sensing tester and displays the obtained concentration information on the display. The detection device for detecting the substation SF6 sensor has the advantages of shortening of the detection time, increase of the working efficiency, ensuring of the safety of personnel, ensuring of the detection accuracy, and maintenance of the safe running of a power grid.