Abstract: In order to study the effect of precast filled wall with polystyrene plate horizontal joint on the seismic performance of shear wall, quasi-static tests of 4 pieces of shear wall specimen with the same size were conducted. Three specimens are shear wall specimens with cast-in-place walls at both ends and precast walls with polystyrene board horizontal joint in the middle, and the fourth specimen is cast-in-place shear wall. The test results show that the failure pattern of the four specimens are compression failure of the normal section of the whole wall, but the shear wall specimen with polystyrene plate horizontal joint has vertical cracks through the joint surface of the cast-in-place wall and the precast wall, while the cracks in the middle precast filled wall are significantly less, and the cracks in the middle precast filled wall of the specimen with boundary elements at both ends of the cast-in-place wall are even less. The ultimate drift ratio of the specimens ranges from 1/83 to 1/50. Compared with the cast-in-place shear wall, the yield stiffness of the shear wall specimens with polystyrene plate horizontal joint decreases by 19.4%~61.6%, and the peak stiffness decreases by 37.8%~55.6%, indicating that the precast filled wall with horizontal joint polystyrene plate can effectively reduce the stiffness. The measured peak lateral load of specimens with precast filled wall in the middle is less than that of cast-in-place shear wall, and its eccentric carrying capacity can still be calculated as the whole wall, but the vertically distributed reinforcement of the precast wall is not included. Using the finite element analysis program ABAQUS, the nonlinear numerical simulation and parameter analysis of the specimens were carried out.The simulation results show that the lateral carrying capacity and stiffness decrease, and the deformation capacity increases with the thickness of the polystyrene plate. The lateral carrying capacity and stiffness decrease, and the deformation capacity increases significantly with the decrease of the length of the cast-in-place walls on both sides.