Abstract Perfobond rib shear connector (PBL) is capable of transferring large internal force between steel and concrete components. It has been widely used in composite bridges as a key load-transferring component. In this paper, the load-transfer mechanism of the PBL shear connector group is investigated theoretically and experimentally. An analytical model was developed based on load-slip characteristics of a single shear connector and load-deformation compatibility of a perforated steel plate and concrete component. The model was validated through full-scale connection loading experiments. Test results indicate that the applied load is unevenly distributed to multiple layers of PBL shear connectors in a connector group in the elastic stage, and the load becomes more evenly distributed as plastic deformation of the connectors takes place. The presented analytical model provides an efficient way for analyzing and designing a PBL shear connector group. The analytical results indicate that increasing the n...