Using the VOF method,a numerical model of three dimensional laser punching is constructed based on the thermal flow coupling of the millisecond laser hole making process and the formation law of the hole.In the model,the phase change process of gravity,anti impact force and solid liquid gas involved in the material removal process is considered,and the temperature field,phase field and hole profile change are obtained under different pulse numbers.The simulation results of aperture and aperture are in good agreement with the experiment.The results show that the gas solid liquid interface in the phase field gradually moves down with the increase of pulse number.The presence of backstroke pressure increases the upper aperture and aperture；splashes increase with the number of pulses；the hole is bowl shaped about 0.5mm down.