The invention discloses a leak detection robot for SF6 gas in a substation GIS equipment, which comprises a remote control device, a walking device and a directional leak detection device for the gas arranged on the walking device. The directional leak detection device for the gas comprises an infrared detection module, an ultrasonic detection module, a second control module and a signal transmitting module. The infrared detection module comprises an infrared transmitting module, an infrared reflecting plate and an infrared receiving and processing module. The ultrasonic detection module comprises an ultrasonic transmitting module and an ultrasonic receiving and processing module. Output terminals of the infrared receiving module and the ultrasonic receiving and processing module are respectively electrically connected with an input terminal of the second control module. The ultrasonic detection module and the infrared detection module are arranged on the walking device, so that the leak detection robot for the SF6 gas in the substation GIS equipment not only can detect the leakage of the SF6 gas in time, but also can detect the concentration of the SF6 after the leakage, so as to guarantee safety of personal and equipment to the maximum extent.