Abstract: The models for predicting the thermal and physical properties of the polyetheretherketone (PEEK) composites filled with polytetrafluroethylene and nanometer Al_2O_3 were established by accounting for the effects of the type, content, and construction of the fillers. The effect of the fillers on the rubbing surface temperature rise and friction and wear behavior of the machinery moving parts made of the PEEK composites was also considered. Thus a series friction and wear tests were performed by sliding the nano-Al_2O_3/PTFE/PEEK composite pins against a steel disc so as to get the 3-D temperature distributions of the pins under steady and unsteady states making use of a three-dimensional finite element method (FEM). The effect of the filler content of nano-Al_2O_3 with high thermal conductivity on the thermal properties of the PEEK composites was discussed. The results showed that the numerical simulation solutions based on the FEM were in good agreement with the experimental results. It was feasible to improve the thermal properties of the filled PEEK composites by incorporation of nano-Al_2O_3 at a high content. However, it was imperative to select proper content of the nano-Al_2O_3 so as to acquire excellent comprehensive properties of the PEEK composites.