The invention discloses an aluminum alloy sectional bar door. The aluminum alloy sectional bar door comprises a frame, the frame is composed of four sectional bar frames, and the sectional bar frames are spliced into the frame through sectional bar angle connecting pieces; vertically downward first reinforcing ribs are arranged between a top plate, a bottom plate and a central column, and second reinforcing ribs which are horizontally perpendicular to the first reinforcing ribs are further mounted on the two sides of the central column; and heat insulating layers are arranged in both the top plate and the bottom plate, and heat dissipating fins are mounted on the surface of a crossbeam plate. According to the aluminum alloy sectional bar door, the heat insulating layers are arranged in both the top plate and the bottom plate so that the heat insulating effect of the sectional bar door can be achieved; the heat dissipating fins are mounted on the surface of the crossbeam plate, so that the heat insulating effect of the sectional bar door are further enhanced; the top plate, the bottom plate, the first reinforcing ribs and the second reinforcing ribs are made of aluminum alloy materials, so that the sectional bar door has excellent corrosion resistance, and the service life of the sectional bar can be prolonged; and the crossbeam plate and the sectional bar frames are fixed and fastened through clamping connection blocks, and the structure of the sectional bar is stable.