Large compressor casing with high strength

The invention discloses a large compressor casing with high strength. The large compressor casing comprises a top cover plate, a net cover and an air guide circle, wherein the air guide circle comprises an air guide channel which is welded and enclosed by steel plates, the cross section of the air guide channel is square, the upper part of the air guide channel is large, the lower part of the air guide channel is small, the upper part of the air guide channel transits to the lower part of the air guide channel by virtue of step surfaces, the cross section of the upper part of the air guide channel is equal to a square hole, an air guide ring is welded below a bottom plate of the air guide channel, four inner reinforcing ribs which are uniformly distributed circumferentially are welded above the bottom plate of the air guide channel, both ends of each inner reinforcing rib are respectively connected with two side walls in corresponding corners, and a top cover reinforcing rib is arranged at the bottom of the top cover plate in the circumferential direction of the top cover plate; the square hole is formed in the left part of the top cover plate, a rectangular mounting hole is formed in the right front part of the top cover plate, and reinforcing structures which form T shapes together with the top cover reinforcing rib are respectively arranged between the square hole and the rectangular mounting hole as well as the back side of the rectangular mounting hole. The air guide circle and the top cover plate are prevented from deforming due to long-time use, the normal installation of a fan is guaranteed, and abnormal sound of the fan is avoided in a running process.