A light source module including a planar light source, a heat dissipation medium, and a heat dissipation element are disclosed. The planar light source includes a light box, electrodes, and an insulation layer. The light box has a light emitting surface and a bottom surface opposite to the light emitting surface. The electrodes and the insulation layer are disposed on the bottom surface, and the insulation layer covers the electrodes. The heat dissipation medium is disposed on the insulation layer. The heat dissipation element includes conductive contact portions contacting the heat dissipation medium and a conductive connection portion connecting the conductive contact portions, wherein the orthographic projections of the conductive contact portions and the orthographic projections of the electrodes on the bottom surface are not overlapped by each other, and airflow channels are formed between the conductive contact portions, the conductive connection portion, and the heat dissipation medium.