Display module and display device

The display module comprises an optical waveguide, a first liquid crystal grating and a second liquid crystal grating, the optical waveguide is provided with a light coupling-in area and a light coupling-out area, the first liquid crystal grating is arranged on the face, away from the light coupling-in area, of the optical waveguide, and the first liquid crystal grating is used for controlling incident light of all colors in the optical waveguide to be totally reflected; and the second liquid crystal grating is arranged on one surface, deviating from the light coupling-out area, of the optical waveguide and is used for controlling emergent light of all colors in the optical waveguide to be converged to one point. According to the technical scheme, the first liquid crystal grating and the second liquid crystal grating are arranged on the optical waveguide, the incident light is adjusted through the first liquid crystal grating so that the incident light can meet the total reflection condition of the optical wa