Abstract: In order to study the effect of different tungsten powder particle size on the properties of W-10Cu composites, tungsten powders with particle size of 1.0 μm, 1.6 μm and 2.1 μm were selected to prepare W-10Cu composites, and its microstructure, density, hardness, electrical conductivity and thermal diffusion coefficient were tested. The results show that with the increase of tungsten powder particle size, the microstructure uniformity of W-10Cu composite is gradually improved, the number of closed pores in the microstructure gradually reduces, the density and hardness of W-10Cu composites decrease, and the electrical conductivity and thermal diffusion coefficient of W-10Cu composite increase.