Abstract: A CW laser was used to perform laser polishing experiments on the 304 stainless steel based on the ablation principle， and a good polishing effect is obtained. A two-dimensional transient numerical model was developed by coupling the heat transfer and material vaporization in laser polishing. The evolution of the workpiece surface in laser polishing was simulated. The surface morphology and surface roughness of the workpiece after laser polishing were predicted. The simulation results are close to the experimental ones， and the error is only 8.17%. In addition， this paper studied the distribution of the surface moving velocity of the workpiece in laser polishing， and determined the relationship between the surface moving velocity and the initial surface morphology: the surface moving velocity at the peak position of the surface morphology is larger， while the surface moving velocity at the valley position is smaller， which reveals the mechanism of laser polishing based on ablation principle to reduce the surface roughness of the workpiece.

Key words: laser polishing, ablation, numerical modeling, surface morphology, surface moving velocity