In the construction of cast-in-place box girders of urban overpass bridges, the traditional full hall bracket system is easy to lead to the interruption of the upper span road, so a technical solution that takes into account construction safety and traffic diversion is urgently needed. Taking the Chushan Avenue cross-line bridge in Xiangyang as an example, the combined bracket system of "steel pipe column + section steel + coiled steel pipe" is adopted, and a technical path of parallel construction and traffic by setting up a passage door opening are constructed, and bracket force calculation and construction process control are proposed. The results show that after structural optimization and whole process control, the combined bracket system not only meets the safety requirements of cast-in-place box girder construction, but also ensures the normal passage of the road. The results can provide a technical paradigm for the construction of similar projects in traffic-dense areas.