Abstract: In order to research the influence of various parameters on the forming dimension of thin-walled structural parts in the process of laser induced MIG arc additive manufacturing of aluminum alloys, this paper used the quadratic general rotation combination method to design orthogonal test samples, and established the process parameters (arc current I, stacking velocity v, interlayer temperature T, laser power P) and the size prediction model of the stable area of the thin-walled wall through quadratic regression equations. And the influences of individual process parameters on the forming of the test piece were studied. It was found that the model prediction effect was good. When the arc current exceeded 106 A, the order of influence of parameters on the layer width from large to small were arc current, interlayer temperature, stacking speed, and laser power. The order of influence of parameters on layer height from large to small were arc current, stacking speed, interlayer temperature, laser power.