A method of correcting image distortion of an optical device in a display device and a display device are provided. The method includes: generating a plurality of pre-distorted images having different correcting values based on a same reference image; inputting each of the pre-distorted images into the optical device respectively to generate a plurality of display images in one-to-one correspondence to the plurality of pre-distorted images; comparing each of the display images with the reference image respectively, to obtain a display image having a distortion value smaller than a first threshold with respect to the reference image, and determining a correcting value of a pre-distorted image corresponding to this display image as a distortion value of the display device; and correcting the image distortion of the optical device depending on the distortion value of the optical device.