High-power plasma microwave resonant cavity

The invention relates to a high-power plasma microwave resonant cavity for a PCVD (Plasma Chemistry Vapor Deposition) optical fiber preform machining tool. The resonant cavity comprises resonant cavity shells and a waveguide device connected with the resonant cavity shells, and is characterized in that the resonant cavity is provided with two bilateral symmetric and coaxial resonant cavity shells, wherein the waveguide device is arranged on one side in the middle of the two coaxial resonant cavity shells in the direction perpendicular to the center line, the front end of the waveguide device is connected with the two resonant cavity shells through a binary power meter, the power of a microwave source is divided into two portions by the binary power meter, and the two portions of power are respectively fed into the two coaxial resonant cavity shells. Not only the feed-in power of the resonant cavity can be effectively improved, but also the leakage of microwave can be effectively reduced; two coaxial resonant cavities can produce two plasmas moving longitudinally when a liner tube is machined, thus effectively improving the deposition rate and the deposition efficiency; the fluctuations of deposition glass for the two coaxial resonant cavities in the axial direction can be counteracted to improve the uniformity of a preform and improve the machining precision and the quality parameter of optical fibers; and the resonant cavity is reasonable in setting and simple in structure.