The deformation of welded I-beams includes lateral bending, torsion and wing angle deformation. Good control during welding will reduce deformation, but there is still some deformation. Mechanical correction or flame correction can be used for welding. It is important to prevent distortion. This sheet is not easy to correct. The web plate should be corrected before assembly, and the weld direction on the same wing plate should be the same when welding. At the same time, other anti-deformation measures can be taken to minimize the deformation.