Abstract: Diamond/Cu composites have the advantage of low density, high thermal conductivity and tailorable coefficient of thermal expansion (CTE), then possess a good thermal matching performance with core chips. Therefore, it has a widespread application prospect in electronic packaging with high heat flux density and other fields. However, due to the poor wettability between diamond and Cu, which restricts its application. To improve the wettability between diamond and copper, tungsten-coated diamond particles as the reinforcement particles, which were coated on diamond particles by vacuum micro-evaporation method, and diamond/copper composites were prepared by Spark plasma sintering (SPS) technique. The formation and structure of tungsten coating on diamond (100) and (111) facets, fracture morphology, relative density (RD) and thermal conductivity (TC) of the compo-sites were studied. The results show that the coating surface is uniform, smooth and compact at the high tempera-ture of 1050^oC for 60 min, and the formation of diamond coating on (100) surface is preferentially compared with that on (111) surface, the gradient structure of WC-W₂C-W grows epitaxial on the diamond surface. The fracture mode of the composites is composed of debonding diamond particles from copper matrix and the ductile fracture of copper, and tight interface bonding between diamond and copper are formed. The coat thickness of tungsten-coated diamond particles is 331.46 nm at 1050℃ for 50 min, and the maximum RD and TC of diamond/copper composites are 99.71% and 459 W/(m·K), respectively.