The invention belongs to the field of functional material preparation, and in particular relates to a method for preparing a nickel oxide electrochromism film. The method comprises the following steps: cleaning conductive glass, preparing a precursor solution, and preparing the nickel oxide electrochromism film by using an ink jet machine. The method has the advantages that the nickel oxide electrochromism film is prepared at one step, the process is simple, the cost is low, doping is easily carried out, the nickel oxide electrochromism film which is good in uniformity and density can be prepared in a large scale, and the electrochromism efficiency of the nickel oxide electrochromism film is improved to a large extent.