A thermal damage analysis model of scratches and residual polishing particles on the optical surface is established. The thermal damage properties of optical materials under such complex defects are studied. The finite difference method was used to calculate the light field modulation and temperature field distribution of the optical material surface at different positions of the polished particles at different scales. According to the surface temperature distribution, the thermal damage threshold of the optical material under the corresponding conditions is achieved. The results show that in addition to the influence of the polishing particle radius on the material damage threshold, when the polishing particles are located at different positions in the scratch width direction, the thermal damage threshold of the material will also change significantly. Among them, the polishing particles in the center of the scratch have the strongest modulation on the light field, and are more likely to cause melting damage of the material.