Abstract: The overpass and ramp bridge of the general contracting project for the construction of the NANDA trunk line (Panyu Avenue node Interchange) project are all arc-shaped diagonal web flange plates. During the construction process, the "shaped keel frame and wood formwork support system" is used for the construction of the arc-shaped diagonal web flange plates of cast-in-place box girders, which overcomes the shortcomings of the shaped steel formwork, such as high processing cost, heavy self weight, inconvenient construction, poor stability of the double jointed steel pipe keel and wood formwork, poor lateral resistance, and difficult to control the construction quality. Through the analysis and Research on the support structure form, material, bridge plane curvature radius, stress analysis, installation technology and displacement monitoring, the research shows that the force of the shaped keel frame structure is only 36.7% of the material strength, the vertical deformation can be controlled within l/800, and the horizontal displacement can be controlled within 0.4 mm. The construction period of each support system is saved by about 3 days, and the turnover cost is saved by about 45000 yuan each time.