Abstract: The residual stresses and distortion produced by a circular weld in LF6 aluminum thin plate were analyzed from the viewpoint of mechanics.In order to simulate the residual stresses and distortion produced by a circular weld in LF6 aluminum thin plate,a finite element model was built and a coupled thermal-mechanical analysis was employed.The result shows that the temperature field and the distribution of stress in circular weld are greatly different from the ordinary butt weld.At the start point of the weld,the maximum radial stress can be as high as the material's yield strength.A deduction based on the elastic theory shows that the buckled plate produced 2 circumferential waves.The numerical analysis of buckling shows the same tendency.