Abstract: In order to accurately evaluate the subgrade and pavement condition of the old road in municipal engineering, the emerging nondestructive testing methods such as pavement measuring car, in-vehicle falling weight deflectometer and ground penetrating radar are used to comprehensively evaluate the subgrade and pavement condition of the old road in the rail transit system. With the help of analyzing the internal connection between the condition of pavement distress, underground disasters, and bearing capacity of pavement structure, the strategy for the treatment of road disease is proposed according to the comprehensive evaluating results, which may change the current situation that the design scheme can only be made through pavement indicators and may provide the scientific basis for the recovery design about rail transit road construction.