Microwave Plasma Chemical Vapor Deposition (MPCVD) refers to the high-purity hydrogen (H2) and methane gas (CH4) was piped into a vacuum chamber，the hydrogen generates a plasma fireball under the action of microwave, and the methane gas to open the chemical bond under the action of plasma turns into free carbon atoms (C) and hydrogen atoms (H). The free carbon atoms will gradually be deposited on the diamond seeds at the bottom of the chamber under the action of the powerful plasma, making the seeds grow thicker. Finally, CVD diamond with the same structure and composition as natural diamond was formed.