A method and an apparatus for coupling an optical waveguide to a single-mode fiber are disclosed. The apparatus includes a substrate, a first optical waveguide, a single-mode fiber and a second optical waveguide. The first optical waveguide, the single-mode fiber and the second optical waveguide dispose on the substrate. One end of the single-mode fiber has an optical fiber taper structure. One end of the second optical waveguide is optically coupled to the first optical waveguide. Another end of the second optical waveguide is optically coupled to the single-mode fiber using the optical fiber taper structure of the single-mode fiber.