Taking the railway track maintenance inspection vehicle as the on-board condition, it is installed in the inspection vehicle, and adopts advanced long-distance air coupling antenna technology and high-speed scanning technology to realize the full section inspection of single track tunnel and the full coverage rapid inspection of single side of double track tunnel at the speed of 20 ~ 40km / h. In the maintenance "skylight", there is no need for power failure of catenary, which can effectively detect the tunnel disease and surrounding rock state, the change of lining structure, lining thickness, void and compactness behind the lining.