The utility model discloses a three-dimensional tunnel detection system comprising a 3D laser detection unit, a 2D image detection unit, an LED illumination system, a VR browsing device, a vehicle positioning system and a motion compensation unit, and the 3D laser detection unit collects the contour size of a tunnel through laser telemetry; The 2D image detection unit is provided with three line scanning cameras; The LED lighting system is installed along the outline of a vehicle body, and lighting energy is controlled by collecting brightness feedback of the camera. The vehicle positioning system and the motion compensation unit adopt the encoder and the inertial navigation module, and the inertial navigation module compensates the tunnel size error caused by the movement of the vehicle body, so that the detection precision is ensured, and the position error caused by the vehicle encoder is compensated. According to the utility model, the tunnel change and the tunnel state can be rapidly detected at high frequency, tunnel diseases can be timely checked and discovered, disease causes can be analyzed, and a reasonable treatment and maintenance method is adopted to ensure the safe and smooth operation of the tunnel.