The invention discloses a detecting vehicle for a tunnel, which comprises the detecting vehicle and a propelling system, a braking system, an image pick-up system, an image pick-up system support device, a travel measuring system, an infrared triggering device, a computer and a power supply system which are mounted on the detecting vehicle. The propelling system supplies power for the detecting vehicle and controls the detecting vehicle to run; the braking system supplies a braking force for the detecting vehicle and controls the detecting vehicle to stop running; the image pick-up system support device is used for mounting and supporting the image pick-up system; the appearance condition of the tunnel is obtained through taking photos by using the image pick-up system; the travel measuring system is used for measuring a traveling distance of the detecting vehicle; the infrared triggering device is used for triggering the computer and the image pick-up system to work; the computer receives the information acquired by the travel measuring system and the image pick-up system and stores the received information; and the power supply system supplies electric power for the detecting vehicle. Compared with the traditional manual detection, the detecting vehicle is timesaving and laborsaving and has high reliability; and in addition, detecting results before and after can be contrastively analyzed.