Abstract: Under the combined effects of uncertain construction loads and environmental loads, the bending stiff? ness of joints in prefabricated subway stations exhibits significant nonlinear characteristics, complicating the process of force and deformation evolution at the joints. To reveal the bending deformation development of CHC (Cshaped steel + H-shaped steel + C-shaped steel) steel-concrete composite joints in prefabricated subway stations under the combined action of axial force and bending moment, a new joint mechanical model with five bending modes is proposed. By solving the deformation and its evolution under different bending modes, the strain distribution regions of each bending mode and the identification methods are discussed. Finally, based on the mechanical model and monitoring data, the spatial-temporal distribution characteristics of circumferential joint forces were obtained. The results indicate that the calculated axial force of the prefabricated subway station joints ranges between 0 and 30 MN, and the bending moment ranges between -3 and 2 MN·m. Most of the joints are in Bending Mode I,and the mechanical response of the overall structure is more sensitive to construction loads and backfill influences.