Abstract: A three-dimensional angle interlock (2.5D) is a new structural composite material, which not only has the advantages of high specific strength, specific modulus, delamination resistance and impact damage resistance, but also overcomes the shortcomings of other three-dimensional multi-directional braided composites in the production of complex special-shaped structures. In this paper, based on the construction of a 2.5D shallow cross-bending coupled cell model and the analysis of mechanical properties, it is applied to a pair of cylindrical spur gears to meet the requirements of high strength and weight reduction. The static and kinematic analysis models of gears are established, and the gear optimization design is realized by finite element analysis. The static and dynamic meshing processes are analyzed, and the results describe the changes of contact strength and bending strength during meshing in detail, which provides reference for weight reduction and meshing characteristics analysis of 2.5D braided composite gears.