Abstract: Objective To fully leverage the advantages of prefabricated structures and realize the synchronous construction of the top joints and main body of fully prefabricated CP（central partition） walls, a study is conducted on the synchronous assembly of the top joints of such walls. Method Based on the fully prefabricated CP wall components used in Shanghai Suburban Railway Airport Link Line project, the structure of the prefabricated CP wall top joints is described in detail. According to its structural characteristics, the upper clearance of CP wall body assembly trolley is utilized to analyze the design of synchronous assembly equipment for CP wall top joints in-depth. Each equipment component is elaborately introduced. A corresponding construction process is then developed based on the equipment features, and the developed equipment is applied in practice following the established procedure. Result ＆ Conclusion The developed synchronous assembly equipment ensures simultaneous construction of the top joints and the main body of CP wall, while also enabling controlled movement of the joints along both the longitudinal and vertical directions of the tunnel. The construction process consists of six main steps and is operationally straightforward. Field monitoring results show that the quality of the synchronously assembled top joints meets assembly requirements, and the developed equipment and process can effectively achieve the synchronous installation of the CP wall top joints with the CP wall main body.