Abstract: Cemented ca rbides with different WC grain sizes were prepared by powder metallurgy. The structure and properties of cemented carbide materials with different WC particle size were studied, and high-temperature friction experiments were carried out. The results show that the mean grain size increases with the increase of the WC particle size.The abnormal growth of the WC grains is more obvious, and the grain distribution range is larger. In addition to toughness, in addition, hardness and strength will decrease with the increase of WC particle size. Cemented carbide with WC particle size of 2.5 μm has good comprehensive mechanical properties. Under the friction conditions of room temperature and 350 ℃, the wear rate of cemented carbide with a WC particle size of 2.5 μm is the smallest, but under the friction condition of 700 ℃,and the wear rate of the cemented carbide with a WC particle size of 2.5 μm is similar to cemented carbide with WC particle size of 1 μm, and the wear rate of cemented carbide with a WC particle size of 3.5 μm is about 2.5 times that of other groups.Cemented carbide mainly forms peeling pits, wear debris and oxidative wear at high temperatures, and the formed WO₃ oxide aggravate the wear of cemented carbide.