To load the laser energy reasonably and obtain ultrasonic signal of large amplitude without damaging material surface in the laser ultrasonic testing,it is necessary that temperature field of materials irradiated by pulse laser is numerically calculated. Firstly,theoretical model of laser irradiating material was established. Then,combined heat conduction differential equation with boundary condition,laser energy was loaded on material surface by the form of heat flux,and temperature field was calculated,and it was found that the results of finite element analysis are consistent with those of theoretical analysis. And then,the effect of the mesh size selection on the temperature analysis results was discussed. The calculation method of temperature field and the mesh size selection were given when material surface was irradiated by pulse laser. Finally,stress field analysis results verify the validity and effectiveness of temperature field calculation method.