It has the characteristics of high hardness, high compressive strength, good thermal conductivity and wear resistance, and can achieve high machining accuracy and efficiency in high-speed cutting. The above characteristics of diamond cutting tools are determined by the state of diamond crystals. In diamond crystals, the four valence electrons of carbon atoms bond in a tetrahedral structure, and each carbon atom forms a covalent bond with four adjacent atoms, forming a diamond structure. This structure has strong binding force and directionality, making diamond extremely hard. Due to the structure of polycrystalline diamond (PCD) being a fine-grained diamond sintered body with different orientations, although a binder is added, its hardness and wear resistance are still lower than those of single crystal diamond. However, due to the isotropy of the PCD sintered body, it is not easy to crack along a single cleavage plane.