<p>Strain softening and rheological damage are the internal mechanisms that underlie the large deformation of deep roadway surrounding rocks, with dilatancy occurring concomitantly. In this study, based on elastoplastic and rheological theories and constitutive equations of the BVS (Burgers, viscoplastic, and strain softening) model, the individual, interactive, and nonlinear coupling effects of these three mechanical properties were analyzed. A numerical simulation of an ideal deep roadway was carried out for verification and further research. The results show that both strain softening and rheological damage lead to a notable increase in deformation and the plastic zone. Dilatancy causes a slight increase in the deformation, but seldom influences the plastic zone. Strain softening and rheological damage not only accelerate each other’s progress but also lower each other’s initiation stresses. Dilatancy accelerates the processes of strain softening and rheological damage. These three mechanical properties exhibit a nonlinear coupling effect. A rock bolt system can effectively inhibit the three mechanical properties. Moreover, the field monitoring data of a 1000-m-deep roadway in Kouzidong coal mine indicate that, considering the three mechanical properties simultaneously, the numerical results are closest to the field conditions. Therefore, in roadway analyses, the objective strain softening, rheological damage, and dilatancy should be concurrently considered, particularly in deep areas. Furthermore, during tunneling, timely support should be implemented to efficiently inhibit the manifestation of the three mechanical properties, fully utilizing the self-bearing capacity of the surrounding rock.</p>