Abstract: With a steel-concrete composite joint in pylon, No.1 Bridge is located at the new district south of Mianyang City. Load is transferred between steel and concrete pylon by bearing plate and PBL shear connector. The application of steel-concrete composite pylon in cable-stayed bridge was introduced. The structure characteristics and mechanics behavior of steel-concrete composite pylon were investigated. Based on analogical principle in geometry physics and restriction condition, specimen test of steel-concrete composite joint of the pylon was carried out. With loads exerted according to the ultimate limit state, the stress and deformation of some members of the steel-concrete composite joint were tested. The stress state of steel-concrete composite joint and the slippage between steel and concrete member were obtained. Combining theoretical analysis with the result obtained from the model test, the mechanics behavior of the steel-concrete composite joint was analyzed and the load distribution between PBL shear connector and bearing plate were obtained.