Based on the ground-based simulation facility, the effects of atomic oxygen (AO) irradiation on the structural and tribological properties of pure polytetrafluoroethylene (PTFE) and carbon fiber and MoS2-filled PTFE composites were studied by scanning electron microscopy, X-ray photoelectron spectroscopy, and a ball-on-disc tribometer. The results shown that AO irradiation had significant effects on the structural and tribological properties of pure PTFE, in which the surface morphologies, mass loss, friction coefficient, and wear rate had been changed greatly after AO irradiation. However, it was noticeable that the addition of carbon fiber and MoS2 filler to PTFE could improve the AO resist capacity and tribological properties of PTFE composites significantly. Copyright (C) 2016 John Wiley & Sons, Ltd.