A method for preparing catalyst coating on a metal base plate comprising: thermal-spraying a layer of a-aluminum oxide nano-particles on a metal base plate using a high temperature flame powder spray gun, at a temperature of 2500-3500° C. and a pressure of 0.2-1.2 MPa; coating an aluminum sol, the weight concentration of the aluminum sol aqueous solution being 2-30%, at a pH of 0.5-4, the drying temperature being 50-150° C., the drying time being 0.5-24 hours, the calcination temperature being 200-1200° C., and the calcination time being 0.5-24 hours; immersing in an active component, the immersing temperature being 20-120° C., the duration being 0.5-24 hours, the drying temperature being 50-150° C., the drying time being 0.5-24 hours, the calcination temperature being 200-1200° C., and the calcination time being 0.5-24 hours. The method is suitable for the preparation of various catalyst coatings with active components.