Disclosed herein are a method for expanding a field of view of a head-mounted display device and an apparatus using the method. The method for expanding a field of view of a head-mounted display device projects a virtual image onto an eye of a user who wears the head-mounted display device. The method includes displaying an image using a curved display and a curved optical lens, and enlarging a virtual image corresponding to the image and projecting an enlarged virtual image at a location farther away from the eye of the user than the curved display using the curved optical lens, wherein the curved optical lens is located closer to the eye of the user than the curved display.