Prefabricated steel-UHPC composite bridge deck is a new deck structure system that places the longitudinal rib at the upper layer and forms PBL shear connectors.This structure can be prefabricated in the factory and assembled on-site.The adjacent steel beams are integrated by welding，and the cast in-situ UHPC wet joints connect the adjacent UHPC bridge decks.However，these wet joints represent the structure's vulnerable segments but with little research.To this end，a full-scale model test has been conducted to study the flexural behavior of the wet joints in a steel-UHPC composite bridge deck in a practical project.The Abaqus finite element model was established and verified based on the test results.With experimental validation，the parameters analysis of the finite element model，including the wet-joint simulation method，steel panel thickness，UHPC thickness，and inclination angle of the dovetail tenon，were analyzed.In comparing the stiffness calculation equation within the American Society of Civil Engineers （ASCE ），Building Code Requirements for Structural Concrete （ACI），and the Chinese Code GB 50010 —2010，it is discerned that the calculated values in the Chinese code are closer to the test values.Based on the flexural stiffness calculation equation for ordinary reinforced concrete beams，the corresponding parameters are modified according to the test data，and the theoretical r esults are verified with the finite element results.The results show that the wet joints of the steel-UHPC composite bridge deck have excellent ductility and stiffness.Using friction behavior to simulate a wet joint interface has low calculation costs and well-agreed results.Increasing the thickness of the steel panel or UHPC can effectively enhance the stiffness and bearing capacity of the structure.In contrast，the impact of the inclination angle of the dovetail tenon on the structure's stiffness and bearing capacity is minimal.After parameter modification，the modified calculation equation of flexural stiffness can more accurately predict the mid-span deflection compared with the results by ordinary concrete specification.