The simulation of long pulsed laser drilling process is done by using the element birth and death method of ANSYS. According to the recoil force of evaporation on the heated surface, a model of ejection of melted materials is built. After coupled solving the two-dimensional axisymmetric differential equation of heat conduction and one-dimensional Eulerian equation of fluid motion by finite element and finite difference method respectively, the results of temperature field and flow field with temporal variation are obtained. The whole shape of the hole will appear by excluding the expelled element during computation, and the result accords with the experiment in literature. The simulation result explains that the irregular shape at the bottom of the hole and a trumpet shaped entrance appearing in the experiment are induced by the interruption of melted liquid within the thin melted depth and the tension between ejected liquid and melted materials adjacent to entrance， respectively.