A method of manufacturing onion pulp according to one embodiment of the present disclosure may include generating a ground onion product by grinding onions to remove sugar and sulfur components from the onions, mixing and stirring jelly powder and purified water at a predetermined ratio, heating a primary mixture in which the jelly powder and the purified water are mixed, stirring the primary mixture with the ground onion product, molding a final mixture, including the stirred jelly powder, purified water, and ground onion product, after placing the final mixture on a mold, and drying the molded final mixture.