Abstract: Diamond/copper composite materials exhibit excellent thermal matching performance with semiconductor chips due to their excellent low density, high thermal conductivity, and controllable coefficient of thermal expansion (CTE) characteristics, and have important application value in the field of high-power electronic packaging. However, the extremely poor wettability between diamond and copper substrate leads to a significant increase in interfacial thermal resistance, severely limiting the thermal conductivity efficiency of composite materials. To improve the wettability between diamond and copper matrix in diamond/copper composite materials, this study used tungsten metal powder and tungsten oxide powder as raw materials, and used thermal diffusion method to coat tungsten metal layer on the surface of diamond particles to prepare tungsten coated diamond. Scanning electron microscopy was used to observe the microstructure of the coating surface, X-ray diffraction was used to analyze the phase structure of the coating, and EDS energy spectrum was used to analyze the distribution of coating elements. Analyzed the microstructure, phase composition, and plating mechanism of the coating, and explored the influence of different plating temperatures and raw material quality ratios on the quality of the coating. The thermal diffusion method can be used to deposit a tungsten metal layer on the surface of diamond, and the obtained tungsten coating presents a uniform and continuous dense structure. SEM and EDS analysis show that the coating is well bonded to the diamond substrate, and no obvious defects are observed. The coating is composed of WC, W2C, W and other phases, and grows epitaxially on the surface of diamond, forming a gradient transition layer with WC-W2C-W structure from inside to outside. The coating temperature significantly affects the density of the coating (in the range of 800-1200 ℃). As the coating temperature increases, the coating tends to become denser. When the temperature rises to 1150 ℃, the coating quality is optimal. When the temperature reaches 1200 ℃, the diamond surface is severely carbonized and the coating is prone to peeling off. The tungsten element content on the surface of the coating is nonlinearly related to the proportion of metallic tungsten in the raw material, reaching a peak (100 at.%) at m (diamond): m (W): m (WO3)=1:1.2:1. Excess metallic tungsten raw material (m (W)/m (WO3)>1.5) can lead to a decrease in gas-phase transport efficiency and hinder the reaction between tungsten oxide vapor and carbon atoms on the diamond surface. The optimal conditions are a plating temperature of 1150 ℃, a holding time of 1 hour, and a raw material mass ratio of m (diamond): m (W): m (WO3)=1:1.2:1. At this time, the coating is evenly distributed and the most dense.