This study investigated the loading mechanism of SPFRC shear walls by conducting low-cycle repeated loading tests on two steel-polypropylene hybrid fiber reinforced concrete (SPFRC) shear walls and one reinforced concrete (RC) shear wall. Furthermore, this study analyzed the impact of fiber content and axial compression ratio on the failure mode, shear carrying capacity, ductility, and energy dissipation capacity of the shear walls. The test results show that hybrid fibers effectively restrain the development of cracks in shear walls, and improve the shear carrying capacity, deformation capacity, and energy dissipation capacity of the shear walls. Considering the contributions of hybrid fibers, horizontal and vertical distributed steel reinforcement, concrete diagonal struts, and concealed columns to shear carrying capacity, a calculation formula for the shear carrying capacity of SPFRC shear walls has been established based on the truss-diagonal brace mechanism. This formula has been validated using data from this study and relevant domestic literature. The average ratio of measured shear carrying capacity to calculated values is 1.01, with a standard deviation of 0.17, indicating a good agreement between them.