In order to study the mechanical properties of steel-concrete joint section of composite shear connectors, the first railway hybrid girder cable-stayed bridge in China was taken as the research background, and numerical simulation and model test were used to investigate the static and fatigue properties of steel-mixed bond concrete joint section and its composite shear connectors. The results show that it is necessary to pay attention to the structural details of steel- concrete joint section to avoid local stress concentration. The shear studs play a major role in shear transmission. Compared with the composite shear connectors, the load of the bearing plate will increase with only PBL shear connector used. The mechanical behavior of the shear studs at the bottom plate is consistent with the results of the push out test, while the mechanical behavior of the shear studs at the top plate is different from the results of the push out test due to the quality of concrete pouring. After the fatigue test, the stress level of the shear stud under greater stress at the bottom plate increases more and enters the elastic-plastic stress state. The stress level of the PBL shear connectors under greater stress increases, but the overall stress level is low. It is concluded that the steel-concrete joint section with composite shear connectors has rational mechanical behavior, and its design can provide reference for other similar projects.