The invention discloses a line recognition module, a line recognition device and a display device, and aims to provide a line recognition module based on a total reflection principle and increase application scenes of the line recognition module. The embodiment of the invention provides a line recognition module. The line recognition module comprises a light source, a light guide layer, an opticalsensor layer and a light-transmitting cover plate, wherein the light guide layer, the optical sensor layer and the light-transmitting cover plate are stacked in sequence. Wherein the light guide layer is provided with a first surface facing the optical sensor layer, a second surface deviating from the optical sensor layer, and a side surface connecting the first surface and the second surface; the light source is positioned on the side surface; and on one side, deviating from the optical sensor layer, of the light-transmitting cover plate, the refractive index n0 of the medium adjacent to thelight-transmitting cover plate is smaller than the refractive index n1 of the light-transmitting cover plate.