The invention relates to the field of aluminum alloys, in particular to a method for preparing a wave-absorbing functional protecting 
coating on the surface of an aluminum 
alloy and various coatings prepared by the method. The method comprises the following steps of: preparing a micro-arc oxidized 
ceramic layer on the surface of the aluminum 
alloy; and then compounding a wave-absorbing 
coating on the surface of the oxidized 
ceramic layer to prepare the aluminum 
alloy wave-absorbing functional 
coating with 
corrosion resistance and a wave-absorbing function, the 
ceramic layer with a compact 
microstructure is prepared by the method, and the 
corrosion resistance of the aluminum alloy is obviously improved. The wave-absorbing coating compounding technology has the effect of sealing the porous ceramic layer, so while the 
corrosion resistance of the ceramic layer is improved, the wave-absorbing function of the ceramic layer is achieved. In addition, the absorption strength and an absorption peak 
frequency interval are effectively changed by adjusting the type, the content and the electromagnetic parameters of a wave-absorbing agent and the thickness of a coating. The comprehensive coating prepared by the method has the characteristics of high corrosion resistance, firm 
surface bonding strength, wide electromagnetic wave-absorbing frequency range and the like, and can be widely applied to fields, such as 
aviation, 
spaceflight, military industry and electronic products.