The invention relates to a bridge frame, and particularly relates to an aluminum alloy bridge frame comprising side plates and connecting rods. The bottom parts of the side plates are provided with fixed grooves. The bottom parts of the fixed grooves are provided with screw holes. The side plates are fixed on the two sides of the connecting rods through screws, and the end parts of the connectingrods are arranged in the fixed grooves. There are multiple connecting rods which are equidistantly arranged. The aluminum alloy bridge frame is simple in structure, low in weight, high in strength, convenient to install, wide in range of application, great in universality, convenient to assemble and low in cost.