Abstract: Prestressed grouting between double-layer concrete linings of water conveyance tunnel can improve the bearing capacity of the structure, but the bearing mechanism of this kind of grouting prestressed lining structure has not been systematically explained. Based on the elastic theory, the mechanical analysis model of grouted prestressed lining considering the deformation coordination relationship is established by using the load structure method. Through the stress analysis of lining structure, the mechanism of prestressed grouting to improve the bearing capacity of lining structure is revealed, and the judgment formula of circumferential tensile stress of lining structure and the relationship between circumferential tensile strength and grouting prestress are deduced. The rationality of the theoretical method is verified by finite element numerical simulation, and the quantitative influence law of grouting prestress on lining structure is analyzed according to engineering cases. It is found that the maximum internal water pressure that the structure can bear is approximately linearly positively correlated with the grouting prestress and external water and soil pressure. The radial deformation and circumferential stress of the inner lining structure decrease with the increase of grouting prestress, while the radial deformation and circumferential stress of the outer lining structure significantly increase with the increase of grouting prestress. This analysis and calculation method considering critical conditions reveals the bearing mechanism of grouting prestressed lining structure, which can provide a theoretical basis for the mechanical analysis and structural design of this type of water conveyance tunnel.