In order to reduce the thermal expansion coefficient of polymeric friction pair materials and expand their applications in a wide temperature range, GF/UHMWPE composites were prepared by hot pressing with untreated and silane coupling agent KH570- modified glass fibers (GF) modified with ultra- high molecular weight polyethylene (UHMWPE). The microstructural differences between the two fillers were characterized by FT- IR; the melting point and crystallinity of the composites were analyzed by differential scanning calorimeter (DSC); the thermal expansion rate and thermal expansion coefficient of the composites were determined with the help of thermal expansion meter (DIL), and the tribological properties of the composites with different mass fractions were investigated under dry friction environment. The results show that the GF modified with KH570 formed a stable Si—O—Si structure, which improves the bonding with the UHMWPE matrix; GF can effectively improve the thermal expansion performance of UHMWPE due to its low thermal expansion coefficient and its ability to form a strong force with polymer chains; the friction coefficient of GF/UHMWPE composites decreases and then increases with the filler content, and the wear coefficient increases with the increase of filler content. At the same amount of filler, GF composites modified with KH570 have better interfacial adhesion and comprehensive properties than untreated GF/UHMWPE composites.