Abstract: Several thin-walled parts made by 20 overlayers were produced on base plates with different thicknesses. Results show that all the width of the overlaying weld canbe stable of 7.30 mm. Moreover, the stable weld width is not affected by the thickness of the base-plate. It is suggested that the various height from the weld to the base-plate heat sink ultimately contribute to the unstable-width varying weld near the base-plate. To adjust the weld width to anunstable-width zone, three kinds of control strategies were conducted. By using the optimized control strategy, the variance can be limited in 0.24. According to the parameters control curve, the heat sink effects exhibit a concave distribution along the height direction. Moreover, the radius of curvature increases with the increase of the thickness of base-plate.