In order to explore the influence of process parameters, scanning method and groove shape on the thin-walled parts manufactured by laser additive manufacturing, based on the ANSYS finite element analysis software, the temperature field and stress field of the thin-walled 316L stainless steel thin-walled parts manufactured by laser additive manufacturing were analyzed by numerical simulation. The results show that a certain component of residual stress will increase if the laser power and scanning speed are too large or too small; the use of vertical cross-scanning method can reduce the residual stress, but it may cause excessive stress in the bonding area between the repaired area and the substrate. This leads to the initiation of cracks. Comparing the stress distribution of the two groove shapes, the edgeless groove shape can reduce the stress concentration in the bonding area and effectively reduce the deformation of the substrate, revealing that the substrate is deformed during the remanufacturing process. Deformation mechanism, and finally designed experiments to verify the influence of different groove shapes on the quality of laser additive remanufactured samples. The experimental results show that a good metallurgical bond is formed between the base material and the repaired area in the shape of the arc groove, which verifies the correctness of the simulation.