The effective coupling between waveguide and optical fiber is the key to the commercialization of integrated optical devices. The coupling efficiency not only directly affects the performance of these optical components, but also is a problem that must be solved in optical fiber communication and integrated-optics fields. In the case of fiber and waveguide in alignment, the mode-field mismatch loss is the main factor affecting the coupling efficiency. We mainly review some domestic and foreign methods of coupling between waveguide and optical fiber, including the wedge-shaped coupler, lens coupler and grating coupler. Summary and comparison are given for these methods. The result shows that a simply-fabricated reverse cone-shaped coupler has an absolute advantage in improving the coupling efficiency, so it has a higher application value in optical-fiber communication and integrated-optics field.