Abstract: In order to investigate the influence of filler content on the tribological properties of Cu/polytetrafluoroethene (PTFE) composites, the Particle Flow Code in 2 Dimensions (PFC2D) was employed to simulate and analysis the processes of the friction and wear of PTFE-based composites with different Cu contents sliding against 45^# steel. The friction transfer and wear of Cu/PTFE composites were mainly studied. The simulation results show that the transferred particle layer is formed on the surface of 45^# steel when Cu/PTFE composites form friction pair with 45^# steel. The wear of PTFE-based composites can be reduced effectively by the formation of transferred particle layer. On one hand, the addition of Cu particles can promote the formation of transferred particle layer by "pinning" effect of self-transition. On the other hand, due to the improvement of composite integrated strength, the addition of Cu particles produces an inhibition to the formation of transferred particle layer. Therefore, the moderate addition of Cu is beneficial to the formation of transferred particle layer. However, this effect will be reduced when the content of Cu is too high. Meanwhile, the wear of PTFE-based composites is reduced effectively due to the addition of Cu particles, and antifriction effect becomes better along with the increasing of Cu content. When the mass fraction of Cu particles is 50%, the number of the wear particles of PTFE-based composites is decreased to nearly half of the pure PTFE.