The utility model relates to an MD high-clear digital television, and consists of a machine case, a system circuit board, an optic-projecting system and a displaying screen, wherein, the optic-projecting system comprises an optic engine arranged on a support of a lower hollow cavity of the machine case, and also a reflecting lens arranged inside the hollow cavity at the upper part of the machine case. The support comprises a bottom plate and a sloped supporting faceplate. A clapboard is arranged between the hollow cavities at the upper and lower parts of the machine case. The support also comprises a vertical connecting plate, both ends of which are provided with lateral plates. An axle is connected between the lateral plates at the two ends of the vertical connecting plate, which can be vertically and flexibly connected with one end of the bottom plate. The other end of the bottom plate is fixedly provided with two supporting rods. A lower lateral end of the supporting faceplate is articulated onto the axle, and an upper lateral end can be connected with the supporting rods through moving around an axial angle. A through hole is arranged on the clapboard so that the optic engine can pass through while being installed and maintained. A dust-proof cover is sealed and connected between the circumference of the through hole and a neck part of the optic engine lens. The position and a projecting angle of the optic engine lens can be adjusted through adjusting the support. The arrangement of the dust-proof cover has effective dust-proof performance for the optic engine lens, the reflecting lens and the internal surface of the displaying screen.