Abstract: Composite fine-tooth structure is an important solution to break through the traditional lightweight structure of metal elastic support, transmission shaft and gear. It has high requirements for bearing performance under complex loads, and the ply design and high-performance manufacturing of fine-tooth structure are the key. In this paper, the simulation model of typical fine tooth structure is established, and the optimization design of fine tooth ply structure is carried out. The influence mechanism of ply mode on the bearing capacity and failure mode of fine tooth is analyzed. The influence of molding process, carbon fiber strength grade and prepreg resin content on the bearing capacity of fine tooth is studied. The results show that the ±45 ply achieves the optimal balance between the bearing stability and the preparation feasibility, which can avoid the problems of resin-rich and difficult molding in the teeth, and is the optimal ply scheme for the radial ply structure of the fine teeth. The optimum molding process parameters were determined by orthogonal test to be 385℃ and 6 MPa. At this time, the internal fibers of the fine teeth were evenly distributed, with no obvious pores and resin-rich areas. In addition, it is found that increasing the grade of carbon fiber and changing the resin content of prepreg can effectively improve the bearing capacity of the fine tooth structure. The bearing capacity of T1100 carbon fiber reinforced composite fine tooth is 18.7% higher than that of T700. The bearing capacity of 28wt% resin content prepreg molded fine tooth structure is 31% and 13.5% higher than that of 22wt% and 34wt% resin content prepreg respectively. In this paper, the integrated design of ply-forming process and high-performance preparation of thermoplastic composite fine tooth structure are realized, which is of great significance to promote the reliable application of high-performance construction of precision transmission and load transfer of composite materials in military weapon systems, high-end equipment transmission, meshing and connection parts.