Abstract: In order to study the effect of wear on the macroscopic elastic constants of fabric liners made of polytetrafluoroethylene (PTFE) and fabric (Kevlar) as well as phenolic resin matrix, the microscopic geometric models of different wear stages were established in combination with the microstructure of the twill liner based on the mathematical model and the volume averaging algorithm in the micro mechanics of composites. Based on the geometrical parameters and the elastic constants of the fibers, the volume fraction and the correlation matrix of the fiber bundle and the matrix were calculated by MATLAB. Realizing the transformation of the elastic constants of the local coordinate system and the global coordinate system of the twill fabric liner, the elastic constant calculation model of the liner in the unworn stage was constructed, and the correctness of the method was proved by an example. The maximum error between theoretical and experimental values is 5.88%. On this basis, according to the structure and the wear depth of the liner, the wear was divided into six stages, and the elastic constants calculation models of different wear stages were established.