Optical waveguide jig and preparation method of optical waveguide

The invention relates to an optical waveguide jig and a preparation method of an optical waveguide. The optical waveguide jig comprises a first mold and a second mold which are arranged in a stacked mode. The side, close to the second mold, of the first mold is provided with a pattern part and a first stop part located on the periphery of the pattern part, and the pattern part is provided with a first surface; the side, close to the first mold, of the second mold is provided with a supporting part and a second stopping part located on the periphery of the supporting part; at least part of orthographic projection of the second stop part on the first mold is overlapped with the first stop part; the supporting part is provided with a second surface, the second surface faces the first surface, and the second surface is used for bearing the optical waveguide; wherein the first stopping part abuts against the second stopping part, and a first gap is formed between the first surface and the second surface. According