Abstract: The main tower of the Xinshi Jinsha River Bridge use the cable-stayed structure of steel anchor beams and steel corbels. The steel anchor box structure is welded onto upper chord of the steel beam. Due to the large number of thick plate welding, fusion welding and filling in a narrow space, huge stress is caused.As a result, construction operations, welding deformation control and welding quality control are difficult. By analysing the relationship between the welding sequence and welding deformation of steel anchor beams, steel corbels and steel anchor boxes,corresponding control measures were taken, and finally a reasonable welding process was developed.The welding quality and manufacturing precision of the anchorage structure of the Xinshi Jinsha River Bridge are guaranteed.