The invention relates to an air guide device with adjustable height for a heavy-duty truck. The air guide device comprises an air guide sleeve front bracket which is laterally fixed to the front end of a top cover of a driving cabin, an air guide sleeve rear bracket which is laterally fixed to the rear end of the top cover of the driving cabin, and an air guide sleeve which is located right above the top cover of the driving cabin, wherein the air guide sleeve is hinged to and mounted at the top end of the air guide sleeve front bracket through hinging brackets I, and is hinged to and mounted on connecting rods through hinging brackets II; a plurality of adjusting holes are formed in the lower ends of the connecting rods in a longitudinal direction at intervals; each bolt penetrates the corresponding adjusting hole to be fastened to the air guide sleeve rear bracket; when the bolts penetrate through the adjusting holes in the most upper ends to fix the position of the air guide sleeve, the inclination angle of the air guide sleeve at the moment is minimum; and when the bolts penetrate through the adjusting holes in the most lower ends to fix the position of the air guide sleeve, the inclination angle of the air guide sleeve at the moment is maximum. According to the air guide device disclosed by the invention, through changing the oblique height of the air guide sleeve, the air guide device is suitable for heavy-duty truck vans of different heights, and height adjustment is simple and convenient; and an effective air guide curve is formed by the streamlined shape of the air guide sleeve, so that the effects that the wind resistance is reduced, and the oil consumption of the whole heavy-duty truck is reduced are obvious.