Tribological behaviors are system responses that not only depend on material properties but also hinge on external environmental factors. This work investigated the tribological behaviors of FeCoNiCrAlx (x = 0.1, 0.5, 1) sliding against Si3N4 ceramics under high temperature conditions. According to experimental findings, the tribological properties of FeCoNiCrAlx were enhanced as the Al element content increased, particularly FeCoNiCrAl1 could resist the material softening under high-temperature conditions to enhance the wear resistance. Based on the friction coefficient changes, wear morphology, phase composition, and chemistry element, the high-temperature wear mechanisms of FeCoNiCrAlx were discussed including adhesive, attrition, and oxidative wear. These new studies will lead to the further improvement of tribological data of high-entropy alloys.