The thermal damage of mouse skin under different output power of 1064 nm laser was studied by experiment and theoretical analysis. The degree of thermal injury of mouse skin tissue was evaluated by dermoscope and optical coherence tomography (OCT), and the theoretical analysis was made according to Arrhenius thermal damage equation, and the results were compared with the experimental results. The results show that when the laser’s continuous irradiation time is 400 ms and the laser output power density is less than 958 W/cm², there is no obvious damage; when the laser output power density is 958-1160 W/cm², the damage is white blister-like; when the laser output power density is 1160-1370 W/cm², the damage is a shallow pit-like macula with a circle of bulging white skin blisters around the damage spot; when the laser power density is at 1370-2190 W/cm², the damage is a red pit-like spot, and there is black-yellow eschar around the injury spot.