Considering the soft rock roadway under the lining effect, based on the unified strength theory criteria, combined with the three-zone model of surrounding rock deformation and the three-stage strain softening model, an analysis has been made of the influence of such factors as intermediate principal stress, cohesion, and lining effect, with analytical solutions for stress, plastic zone size, and radial displacement of roadway surrounding rock derived, followed by an analysis of the influence of various factors on surrounding rock deformation through engineering examples. The results indicate that various factors such as the intermediate principal stress have a significant impact on the plastic zone of the surrounding rock in the tunnel, controlling the magnitude of cohesion, increasing the intermediate principal stress, and improving the elastic modulus of the lining can effectively control the deformation of the surrounding rock and the development of the plastic zone within a certain range.