The Commercial Air Purifier is designed to be used in indoor public places to change the air quality. The rounded corners are designed to reduce the risk of injury caused by sharp corners. The all round air vents can increase filtering area and thus raise filtering efficiency. The commercial air purifier adopts the modularization design, so that the different quantity requirements of various public places can be flexibly satisfied. The full metal shell with surface oxidation treatment makes the air purifier firm and durable in public places. Also, the brand new aluminum profile extrusion applied can improve production efficiency.