To analyze quantitatively the heat effect of laser and bio-tissue by using available model is propitious to estimate clinic effect and optimize laser parameter. The most researches for the heat interaction were limited on temperature distributing without mass flow process, and few researches on heat interaction with high-power pulse laser. The finity difference method was used to simulate the distributing of light, heat source, temperature fields and vaporizing depth along with time. The relations of temperature rise, vaporizing efficiency versus power density, irradiation time, pulse width, repeat frequency, were analyzed theoretically. The simulation results were compared with experiment and indicated that the absorption coefficient of tissue influences greatly aggradation of laser energy, heat transfer and vaporizing on tissue surface. The highest temperature point locates on tissue surfaces, and change of temperature field is induced by the different cooling condition on surface. The theoretical model is reasonable and may give some references to the laser bio-tissue vaporization.