Ladder bottom plate for subway overhead line system shield trackless construction

The utility model belongs to the technical field of railway engineering, and particularly relates to a ladder truck bottom plate for subway overhead line system shield trackless construction. In order to improve the safety of a ladder truck and operators, relieve the safety protection pressure and improve the efficiency during trackless construction of a shield tunnel contact net, the safety protection device comprises a bottom plate outer frame, two sides of the bottom plate outer frame are narrow sides, the other two sides of the bottom plate outer frame are wide sides, and the wide sides of the bottom plate outer frame are provided with four roller penetrating holes for allowing rollers to penetrate through. The narrow edge of the bottom plate outer frame is fixedly connected with a ladder truck frame connecting rod, four stiffening supports are arranged in a rhombus shape in the mode that the midpoints of the four edges in the bottom plate outer frame are connected, four stiffening supports are arranged a