The temperature field, molten flow and gas jet induced convection and heat exchange boudary conditions are important for material surface formation quality and tissue transformation in laser texturing. Then a three-dimensional transient numerical model is developed for the heat transfer, convection heat transfer and morphology evolvement of the molten pool during laser surface texturing. Based on the software Fluent, the model adopts the enthalpy and volume of fluid (VOF) methods to solve the solid-liquid phase boundary and free surface flow numerically. The evolution of phase interface and free surface, and the effect of assist gas on the surface profile are analysed. The heat transfer and fluid motion, as well as the surface shape and scale of the molten pool are numerically approached for the pulse laser texturing with different processing parameters. The numerical simulation was consistent with the result of laser texturing experiments.