In order to study the effect of counterpart surface roughness on tribological properties of nanoparticles filled polyphenylene（PTFE）composites under dry friction condition, cold compression molding and hot sintering were used to prepare nano-SiO₂ filled PTFE composites. The tribological properties of nano-SiO₂ filled PTFE composites sliding on three kinds of counterpart (GCr15) surface with different surface roughness were evaluated by LSR–2M reciprocating friction and wear tester. The morphologies, microstructures and chemical compositions of the transfer films and debris were characterized by optical microscopy (OM), scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS), in order to reveal the friction transfer mechanism of nano-SiO₂ filled PTFE composites from the microscopic perspective. The experimental results showed that the friction coefficients of pure PTFE and different content of nano-SiO₂ filled PTFE composites increased with the increase of the surface roughness of the steel counterpart, while the friction coefficients were relatively small on the counterpart surface with roughness 0.1. The addition of nano-SiO₂ effectively reduced the wear volume of PTFE on three different counterpart surface roughness, when the filling ratio was 0.5%, the best tribological property was obtained on the counterpart surface with roughness 1.2, the running-in time was nearly 10 minutes shorter than pure PTFE, and the wear resistance was 33.3% higher than that of pure PTFE. There was a synergistic effect between the content of nano-SiO₂ and the counterpart surface roughness, the friction pair that compose of PTFE composites filled with nano-SiO₂ and steel discs counterpart with certain surface roughness can effectively promote the friction transfer of composites, therefore the transfer films with high coverage, uniformity, continuity, rough surface and consistent with the direction of friction on the counterpart surface were formed, which is beneficial for reducing the wear of materials.