Aizhai Bridge is a steel-truss stiffened girder single-span suspension bridge with the main span arrangement of 242m+1176m+116m. It crosses the Dehang Grand Canyon, the terrain on both sides of the canyon is steep, and the design elevation of the bridge floor is about 355 meters different from the ground level. In order to overcome the difficulty of poor transportation conditions, the construction scheme of rail cable sliding frame and beam method is put forward. It uses the main cable of the suspension bridge as a load-bearing structure, and the permanent suspension cable is connected to the tensioned rail cable supported by the temporary sling as a track. The beam carriage moves the steel girder stiffening beam section on the rail cable, reaches the position to be installed, and vertically lifts and installs it with the help of the cable hoist. In this paper, the sliding-frame beam system of the rail cable and its scale model test and full scale model test are introduced. At the same time, the design and test of the cable hoist are also described. The test and engineering application results show that the rail cable sliding frame beam method can quickly realize the erection of the main beam of the suspension bridge, and has good safety and economy, and has broad application prospect and popularization value.