Abstract: Laser energy coupling coefficients of surface of aluminum target were obtained by different technics, such as sandblast, roughening by sand paper and plating gold. According to classical Fourier heat conduction equation, the theoretical model for numerical simulation on temperature fields of aluminum target under intensitive laser was built up. The software based on finite element method was used to analyze temperature field distribution of aluminum target under continuous-wave (CW) laser irradiation. Temperature field distribution of aluminum target with different surface roughness was calculated, when incident laser was regular beam or Gauss beam. In authentication test, the maximum temperature rise of back surface at the center of laser beam which irradiated on surface of aluminum target was measured by thermocouple. Comparison of the numerical results with the experimental results shows the availability of the finite element method. Analyzing ablation morphology after laser irradiation, the results are coincident with the numerical simulation.