The invention discloses a ZnO nanowire array preparation method. The method comprises the following steps that 1, an Al block and a Zn block are smelted into an alloy and rolled to be an alloy sheet,and then the alloy sheet is subjected to primary quenching; 2, the alloy sheet obtained in the step 1 is subjected to solution treatment, and then secondary quenching is conducted to obtain a profile;3, the profile obtained in the step 2 is subjected to free corrosion in a strong alkaline solution; 4, the profile obtained through free corrosion in the step 3 is heated in the strong alkaline solution for conducting oxidation treatment, and then a ZnO nanowire array is obtained. The material prepared through the method has a neat array structure in all regions, the morphology purity is high, the product is stable and not prone to deformation in air, and very high application value in the fields of piezoelectricity, a micro-nano power supply, field emission, nano-laser, waveguide, an ultraviolet photodetector, catalysis and adsorption is achieved.