Aluminum or aluminum alloy workpiece is used as anode to form alumina thin layer on aluminum surface by electrolysis. Alumina thin layer can improve the surface properties of workpiece or achieve some special functions, such as improving the surface hardness or corrosion resistance, enhancing the temperature resistance of workpiece surface or forming a protective layer, etc. Anodization of aluminum is a mature process. The traditional hard anodization has low efficiency and long oxidation time. Fast anodizing adopts special power supply mode, which greatly improves the oxidation efficiency and shortens the anodizing time. It is especially suitable for the hardening of cast aluminum and other aluminum alloys