The analytical expression of temperature field around inclusion is obtained by establishing the model of temperature field due to the absorption of the single impurity defect in the KDP crystal using Green′s function method based on the theoretical solution of the point source heat transfer model. The influence of pulsed laser parameters on the temperature fieldis analyzed and the model of multi-inclusions absorption in the certain area of KDP crystal is obtained based on the single impurity defect absorption theory. The results show that the temperature variation caused by the inclusion absorption is closely related to the parameters of the pulsed laser. When the distance among the inclusions is less than the thermal diffusivity length in the duration of laser pulses, it will lead to the cumulative effect of temperature field. If the density of the inclusions is large enough, the temperature around the inclusion group will rise rapidly, which will enlarge the possibility of laser induced damage for crystals.