In order to improve the tribological properties of poly(methyl methacrylate) (PMMA) frictional parts, nano-silica (SiO₂) and -titanium dioxide (TiO₂) particle-reinforced PMMA composites were prepared by hot press. The tribological behavior and wear mechanisms of the composite were investigated in dry friction condition. The results show that great strengthening effects are obtained using nano-SiO₂ and -TiO₂ particles to reinforce PMMA composite. The composite exhibits excellent tribological properties. The wear mechanisms change from microcutting wear, multiplastic deformation wear and adhesive wear into abrasive wear and brittle fracture wear.