Preparation method of filtering membrane

The invention discloses a preparation method of a filtering membrane. The preparation method comprises the following steps: 1) gelatinizing: coating a uniform embossing adhesive to the surface of a base membrane to form an embossing adhesive layer on the surface of the base membrane; 2) embossing, namely pressing an embossing template down, wherein a protruding nanostructure on the embossing template is in contact with the surface of the embossing adhesive layer to form a corresponding patterned nanostructure on the surface of the embossing adhesive layer; 3) etching, namely etching the base membrane with the embossing adhesive layer with an etching machine and etching corresponding holes in the base membrane to form the filtering membrane; and 4) cleaning, namely cleaning residual embossing adhesive on the filtering membrane with an acid solution. According to the preparation method of the filtering membrane provided by the invention, the embossing adhesive is adopted for embossing, so that the filtering mem