Abstract: To address the pronounced spatiotemporal effects on the stress state and deformation of surrounding rock during TBM excavation of inclined shafts through weakly cemented strata, an elastoplastic analytical model of surrounding rock–support interaction is developed by considering surrounding-rock stress release and equivalent support loads. Loads exerted on the surrounding rock by rock bolts, cable bolts, wire mesh, the invert arch, and TBM self-weight are converted into an equivalent uniformly distributed load. By incorporating surrounding-rock stress release, a spatiotemporal evolution model for surrounding-rock deformation in inclined shafts is derived. Physical and mechanical parameters of the weakly cemented rock are obtained from laboratory tests and used to validate the analytical solution. A prescribed function is introduced into a finite-difference numerical model to simulate the progressive release of surrounding-rock stress.It is shown that an intense mechanical response is induced in the surrounding rock during the very early stage of TBM excavation. The support load increases sharply during the first 3 d, and a gravity-induced spatial asymmetry is observed, with the load decreasing in the order of crown, shoulder, and haunch. A joint-support analytical model incorporating construction-sequence lag confirms that treating the load exerted by the TBM main machine as an early floor constraint reasonably corrects the approximately 1 d construction lag of the invert arch, and an early-stage elastoplastic analytical solution for coordinated support is obtained. Similar trends are observed between the measured and theoretical roof displacements, while maximum roof convergences of 49 and 68 mm, respectively, are obtained from field monitoring and theoretical analysis; these values are of the same order of magnitude. The elastoplastic solution incorporating surrounding-rock stress release and field support is verified to describe the development of the plastic zone and plastic displacement. After surrounding-rock stress release is introduced into the numerical simulation, the necessity of considering this effect is verified. The protective effect of support on surrounding-rock deformation is concentrated at the crown and floor; relative to the unsupported condition, the plastic-zone extent is reduced by 14.78%−15.10% at the crown and by 14.99%−15.91% at the floor. Deformation of weakly cemented rock in western China is effectively limited by field support measures. Comparison of the maximum and minimum principal stresses under unsupported and supported conditions shows that stress release in the surrounding rock is restrained by support. These results provide a theoretical basis for designing support schemes and installation timing for inclined shafts in western weakly cemented strata.