Preparation method for anode alumina template having gradient nanometer pore size

The present invention relates to the field of porous anode alumina templates, particularly to a preparation method for an anode alumina template having a gradient nanometer pore size. According to the preparation method, a porous anode alumina template is immersed in an inorganic acid aqueous solution, and then is rapidly pulled out of the inorganic acid aqueous solution to obtain the anode alumina template having a gradient nanometer pore size, wherein the gradient nanometer pore size has a characteristic of large lower portion and small upper portion. According to the present invention, the preparation method has characteristics of convenience and rapidness, and various anode alumina templates having different gradient pore size changes can be prepared by changing the concentration and the temperature of the inorganic acid aqueous solution, and the pulling-out time.