This study obtains W-Cu materials suitable for the electronic packaging by fabricating W-Cu composites with different W contents (such as 60W-40Cu, 70W-30Cu, 75W-25Cu, and 80W-5Ni-15Cu) through selective laser melting. The effect of W content on the microstructure, density, thermal conductivity, coefficient of thermal expansion, roughness, and hardness is evaluated. The results show that the balling phenomenon is common in such four composites. When the W mass fraction is less than 70%, the densification mechanism is rearrangement; connection and contiguity are hardly observed between W phases; heat conduction is preferred in the Cu phases. In addition, when the W mass fraction is higher than 75%, solid sintering is the main densification mechanism, and the heat conduction path contains the constitutional unit of Cu occupying the unit edges and W occupying the unit center. The deviation between the thermal conductivity/coefficient of thermal expansion of W-Cu composites and the theoretical values increases with increasing W content, which also occurs in the cases of roughness and hardness. The obtained densities of 60W-40Cu, 70W-30Cu, 75W-25Cu, and 80W-5Ni-15Cu are 97.9%, 94.5%, 91.6%, and 91.9%, respectively. The thermal conductivities of the four composites are 210.4, 176.8, 152.7, and 121.3 W·K -1·m -1, respectively. Furthermore, the thermal expansion coefficients of the four composites are 11.05×10 -6, 9.33×10 -6, 8.17×10 -6, and 7.02×10 -6 ℃ -1, respectively. The surface roughnesses of the four composites are 9.2, 13.7, 15.2, and 15.4 μm, and the microhardnesses are 183, 324, 567, and 729 HV, respectively.