A new technology is put forward which uses weld with trailing impactive rolling to control the welding stress and distortion of thin component and to prevent welding hot cracking. Via the front and rear impact rollers, impulsive force with a certain frequency is applied to the metal of the weld bead and the weld toe respectively when they are still hot after welding. The front impact roller is concave, which compels the metal of the weld toe to flow towards the central line of the weld. This will counteract the tensile strain which may induce hot cracking. The rear impact roller is convex, which will stretch the longitudinal and transverse compressive strain in the weld that comes into being during welding, and it also can stretch the transverse compressive strain which is engendered by the front impact roller. The equipment is simple and portable. It can control the stress and distortion of both the straight weld and the closed weld. The results of experiment show that this technology can decrease the thin component's welding residual stress greatly and reduce the residual distortion to 1/10 of the ordinary welding, besides the surface of the weld bead is even and smooth, which will reduce the stress concentration on the weld toe greatly.