An optical lens and a head-mounted display device including the optical lens are provided. The optical lens includes a first lens, a second lens, a third lens, a fourth lens, and a fifth lens sequentially arranged from a light exit side to a light incident side. An image generator is disposed at the light incident side. The optical lens is configured to receive an image light beam provided by the image generator. A stop is formed at the light exit side of the image light beam. At the stop, the image light beam has a minimum light beam cross-sectional area. The technical solution of the invention may be used to shorten an overall length of the optical lens, so as to reduce an appearance volume of the display.