A two-dimensional shear force calculation model for hinged joint (HJSFM) taking damage position, cracking length and degree of hinged joints into account was established, in order to quantitatively evaluate the damage degree of hinged joint in the hollow slab girder bridge and provide decision-making basis for subsequent maintenance and reinforcement. In this model, single hollow slab was compared to an orthotropic plate, and the bridge was formed by multiple orthotropic plates laterally connected through hinged joints. The relationship between shear force of the hinged joint and relative displacement occurring across the hinged joint was introduced as the force transfer equation between orthotropic plates. The analytical solution for HJSFM under loads was derived based on Fourier series expansion. Based on the evolution of damage state of hinged joints under design load and overload, a three-level damage rating scheme of light, medium and heavy for hinged joints (HJDRS) was put forward. HJSFM and HJDRS composed the core of damage assessment model for hinged joint (HJDAM). Finally, a finite element model was established to verify accuracy of the shear force calculated by the HJSFM, and the HJDAM was applied to a hollow slab girder bridge with damaged hinged joints. Results show that the accuracy of shear force obtained by the HJSFM can meet the engineering needs and the HJDAM is feasible.