In the simulated vacuum environment of low-temperature and low-pressure, a continuous laser irradiation effect experiment of 1070 nm was carried out on a carbon fiber composite sandwich structure with white paint on the surface of the reflector antenna using a fiber laser as the light source and the morphology characteristics of sandwich structures under different laser loading conditions were obtained. The transient temperature field on the surface of the sandwich was measured by a high temperature infrared imager, and the surface temperature rise of the sandwich was obtained by thermocouple. The relationship between temperature and damage morphology of structural materials was obtained by analyzing the changes of surface temperature field and morphology during laser irradiation. The mechanism of laser action on the sandwich structure of carbon fiber composite and the influence of laser parameters on the morphology of structural materials were studied. The results show that under laser irradiation with a laser power density of about 20 W/cm2, the white paint sprayed on the surface of the front skin first ablates and falls off. As the temperature rises, the resin base of the carbon fiber composite is pyrolyzed, the carbon fiber spallation occurs, the front skin loses its mechanical properties, the rubber film is pyrolyzed, the front skin is separated from the aluminum honeycomb, and the back skin expands and deforms under the action of pyrolysis gas.