In order to improve the geometrical features of the cladding layer and to explore the distribution law of residual stress after laser cladding, we use dilution ratio and width-height ratio as the evaluation indexes. Based on the response surface method, a composite design matrix test with 4 factors (laser power, scanning speed, powder feeding rate and defocusing amount) and 5 horizontal centers is established. The influence laws of cladding parameters on each response value under the interaction of single factor and multiple factors are explored. The research results show that scanning speed and defocusing amount have the most significant influence on width-height ratio, defocusing amount and laser power have the most significant influence on dilution rate, and the interaction between laser power and scanning speed has certain influence on dilution rate. Finally, the correctness of the predictive model is verified by experiments. The optimized morphology and process parameters of the cladding layer are selected for numerical simulation, and it is found that the maximum residual tensile stress in the x direction is 532 MPa and occurs at the end of the cladding layer. In the longitudinal section of the cladding layer, the tensile stress mainly appears in the cladding layer and the heat-affected zone. As the depth increases, the tensile stress gradually decreases and is converted into the compressive stress at the bottom of the cladding layer. However, in the y direction, due to the deformation of the formed parts, the bottom surface of the substrate is subjected to tensile stress.