The current study focuses on performance analysis and structural optimization of the 2.5 D C/C composite finger seal. A micro/macrostructural integrated optimization method of 2.5D C/C composite finger seal is presented. Based on uniform strain assumption the stiffness average method is used to predict the elastic properties of 2.5D C/C composite material. In order to achieve the advantage of the designability of composite material, the microstructure parameters are also as design variables together with the macro structure of finger seal. Considering the two optimization objectives, leakage and contact pressure, are both implicit functions of the structure parameters of finger seal which obtained by finite element method, a Krige model is established to replace the finite element method analysis in each optimization iteration, which could improve the optimization calculating efficiency obviously. By using the multi objective genetic algorithm NSGA-II the 2.5D C/C composite finger seal optimization is implemented availably. An example is given which indicates the leakage and contact pressure of finger seal decrease significantly through the integration optimization of 2.5D C/C composite finger seal which develop a new approach to design finger seal with high performances.