The invention belongs to the technical field of optical switches, and specifically relates to a silicon-based waveguide optical switch based on an amorphous silicon memristive effect and a manufacturing method thereof. According to the main scheme of the invention, the optical switch comprises a silicon-based waveguide, an amorphous silicon layer, a silver electrode and a metal electrode, the silicon-based waveguide is a flat silicon-based waveguide with a ridged convex structure in the middle, the amorphous silicon layer is disposed on the upper surface of the middle ridged convex structure of the silicon-based waveguide, the silver electrode is disposed on the upper surface of the amorphous silicon layer, and the metal electrode is disposed on the upper surface of the planar part of the silicon-based waveguide at one side of the middle ridged convex structure of the silicon-based waveguide. The beneficial effect is that the optical switch has the advantages of small size, is of high stability, is less affected by temperature and voltage fluctuation and has good radiation-resistant characteristic.