Research conclusions: The scheme of the maintenance vehicle presented in this pape is as follows:(1)The maintenance vehicle can travel in walk type by control of the electric plug pin device，with no operation by person on the chord member. The anti rolling device is installed between the the vehicle and the rail to enhance the construction safety and the travel safety. ( 2)The maintenance vehicle can cross the span because the walking wheel box is made in arch shape. In this way，the whole maintenance works can be done by one maintenance vehicle and the maintenance cost can be reduced.(3)The full and safe maintenance can be conducted to the side of the upper arch and web member because the light extension-type suspension cage is used as the side operating platform and the limit protection device is used for the truss. ( 4 ) The technical scheme presented in this paper can provide the reference to the similar works.