The invention provides a device used for researching the influence of SF6 gas humidity on insulator flashover characteristic. The device comprises a fully enclosed experiment tank body, an adjustment device which is used for delivering humidity-adjustable SF6 gas, a conductive clamping part and a dewpoint meter which is used for measuring the SF6 gas humidity. One end of the adjustment device is connected with the tank body and is communicated with a cavity in the tank body. The other end is connected with an external SF6 gas discharge device. The clamping part is a metal electrode and is located in the cavity in the tank body, and comprises an upper clamping part and a lower clamping part. One end of the upper clamping part is connected with one end of an external power supply, and the end face of the opposite end is close to the end face of one end of a detected insulator. One end of the lower clamping part is connected with the other end of the external power supply, and the end face of the opposite end is close to the end face of the other end of the detected insulator. The dewpoint meter is arranged on the experiment tank body, and both ends are respectively located in the cavity in the tank body and outside the tank body. According to the embodiment of the invention, the SF6 gas humidity can be precisely controlled; the number of times of experiment is reduced; and the workload is reduced.