A display device and a light source block used therein are provided. The display device includes the light source block, a film set, and a display panel. The light source block has a reflective surface, a film supporter intersecting the reflective surface at an edge, and a panel supporting surface. The film supporter connects an end of an extremity surface, and the panel supporting surface connects the other end of the extremity surface. The film set is disposed on the film supporter, and the display panel is disposed on the panel supporting surface. The display panel has a display area and a light-shielding unit disposed outside the display area. The edge between the reflective surface and the film supporter falls into a vertical projection of the light-shielding unit.