Polymer friction materials play a vital role in friction pendulum bearings (FPBs) but often experience premature failure due to high wear rates, significantly limiting their service life. This study developed a composite containing nanoscale silicon nitride (Si 3N 4) particles and microscale polytetrafluoroethylene (PTFE) powder. The tribological properties of the composite against an AISI 304 stainless steel (AISI 304 SS) counterpart were characterized using a pin-on-disc sliding tribometer. Experimental results revealed that the composite containing 5% Si 3N 4 exhibited a lower friction coefficient and an ultra-low wear rate compared to pure PTFE. At a sliding velocity of 0.15 m/s and a normal load of 150 N, the wear rate of the 5% Si 3N 4 composite was reduced by 95% relative to pure PTFE. This enhancement was primarily attributed to the dispersion strengthening and load-bearing effects of Si 3N 4 nanoparticles, along with the formation of a more stable transfer film at the friction interface. These results underscore the potential of Si 3N 4 nanoparticles to significantly improve the durability of polymer friction materials in FPBs applications.