This paper presents a numerical method for simulating progressive wear of the carbon-fiber-reinforced carbon matrix composite used in rotary gas seals due to high experimental cost. In this study, the carbon-fiber-reinforced carbon matrix composite wear rates are experimentally measured, and a formula for the carbon-fiber-reinforced carbon matrix composite wear rates and material design parameters (orientation angles and densities) and operating parameters (load and velocities) is fitted as an input to the wear simulation. A finite element incremental wear simulation procedure for the pin-on-disk wear problem is presented by calculating the local nodal wear rate and wear direction and by introducing the Arbitrary Lagrangian Eulerian adaptive meshing method. In the procedure, the relation between the anisotropy of carbon-fiber-reinforced carbon matrix composite and the varied orientation angle is considered. Results show that the calculated wear volume agrees well with the experimental data. And then the numerical methodology is utilized to investigate the effects of time, orientation angle and operating conditions on the disk wear. The developed numerical methodology could be applied to other sliding wear problems in engineering machinery.