In view of a study on the plastic zone radius and stress distribution law of circular roadway surrounding rocks under temperature stress and damage effects, based on the unified strength theory, the calculation formulas can be derived for the stress field, displacement field, and plastic zone range of surrounding rocks under the coupling effect of temperature stress and damage. Combined with concrete examples, an analysis is made of the effects of damage, temperature stress and other factors on the stress and plastic zone range of roadway surrounding rocks. The calculation results show that such factors as damage and temperature stress have a significant impact on the stress and plastic zone radius of the roadway surrounding rocks. Among them, the plastic zone radius caused by the combined effect of damage and temperature stress is the largest, which increases by 8.1% compared with the plastic zone range caused by the surrounding rock stress only. Therefore, it is necessary to explore the radius and stress distribution of the plastic zone of surrounding rock in tunnels under the effects of temperature stress and damage, which can provide a theoretical basis for an optimal support design and stability analysis of tunnel engineering.