The Xianning Yong’an Pavilion scenic spot project is an imitation of the Song Dynasty. There are platform foundations on the first and second floors on the north and south sides of the main building, and there is no platform foundation on the east and west sides. The 4th, 6th, 8th, and 9th floors all have eaves that can be raised outside, and the length of the eaves is about 4 meters. Considering the long construction period and low work efficiency of the antique buildings, the overhanging steel platform support frame is considered as the formwork support for the eaves outside the eaves area, and the full hall scaffolding and protective outer frame are set up on the overhanging platform. The mechanical analysis of the relevant parameters of the support system using the safety calculation software proves the safety of the support system. Considering the long construction period and low efficiency of the antique building, it is considered to set up the cantilever steel platform support frame as the support frame of the eaves outside the cornice area, and set up a full scaffold and protective outer frame on the cantilever platform to ensure the safe production and construction quality.