An image conversion method, a conversion device, and a display system are provided in the embodiments of the present invention. The image conversion method includes: performing word area detection on an image to acquire a detected word area; and performing conversion processing on the image according to the word area to acquire a converted image that has an aspect ratio different from that of an unconverted image. The conversion device includes: a detection unit, configured to perform word area detection on an image to acquire a detected word area; and a conversion unit, configured to perform conversion processing on the image according to the word area to acquire a converted image that has an aspect ratio different from that of an unconverted image. In this way, an important content area of the image may be retained and clearly displayed.