In order to reduce the influence of residual stress on the quality of laser cladding layers, ANSYS software was adopted to establish a single-track model, the effect of process parameters on residual stress of cladding layers were investigated by using orthogonal test, and the optimized process parameters were obtained. The results show that scanning speed and laser power have greatly effect on residual stress, and next come spot diameter. The residual stress was calculated under the optimized process parameter combination, which is reduced to 192MPa. It provides guidance for selecting process parameters in experiments.