Abstract: Abstract: Taking the Chongqing Jingkou Jialing River Bridge, a key control project of the newly built Chengdu-Chongqing Double-track High-speed Railway, as an example, the railway cable-stayed bridge with an all-welded steel box girder structure has extremely strict precision control requirements. The overall precision of the steel box girder mainly depends on the precision control of part cutting, plate unit assembly, and overall assembly, with a focus on controlling welding deformation during plate unit and overall assembly. This paper mainly discusses the key measures taken for overall precision control in aspects such as part cutting, process assembly, and welding deformation. Through in-depth research and the formulation of targeted technical measures, good results have been achieved in the practice of the Chongqing Jingkou Jialing River Bridge.