Abstract: In order to solve the concrete pouring problem of the foundation of ±800 kV Baihetan-Zhejiang Yangtze River crossing project,one of the largest overhead transmission line crossing projects in China,the technical parameters and structural composition of the column special-shaped steel formwork system are comprehensively analyzed,and its performance in practical application and future promotion space are discussed. In view of the lateral pressure as high as 80. 3 kN/m2brought by large span tower foundation pouring on the steel formwork,the structure characteristics of the foundation including new type of inserted steel pipe,axillary area and top shear groove were combined to adapt to the actual pouring sequence of the foundation,and the requirements of easy stripping and high surface quality were considered. The newly designed column steel formwork has high roughness requirements of the inner surface and the attached channel steel truss,which is assembled by mobile crane according to the pouring process and connected by bolts and tie rods. It can meet the requirements of structural strength and surface quality and is convenient for on-site installation of support. Through the actual engineering verification,the foundation special-shaped steel formwork has achieved the expected goal and achieved remarkable results,which provides a research and development idea for the construction of the same type of overhead transmission line large span foundation formwork in the future.