In order to investigate the effect and sintering behavior of microwave on TiB2/Cu composite powder compacts, Cu-5vol%TiB2 and Cu-10vol%TiB2 composites were prepared by microwave sintering. The X-Ray Diffraction (XRD) results show that no new crystal phase appears during the sintering process. SEM results illustrate that TiB2 particles evenly distribute over the composites, but the bad wettability between the Cu and TiB2 results in the interface of the composites not ideal. The density of Cu-5vol%TiB2 sintered sample is higher than that of Cu-10vol%TiB2, but the microhardness is lower. Scanning electron microscope (SEM) analysis of the free-packed powder shows that the microwave sintering of Cu-TiB2 composites starts from the branch side of Cu powders, and then as the sintering continuing, the composites gradually realize the densification through atomic surface diffusion and bulk diffusion. At the same time, liquid phase sintering occurs in the experimental conditions.