The invention discloses a method for preparing an antifreeze liquid film and belongs to the technical field of agricultural implements. According to the method disclosed by the invention, maize strawsserve as raw materials, and yeast bacterial suspension serves as zymocyte, so that glyoxal is reduced into ethylene glycol. Since the freezing point of the ethylene glycol is 10 DEG C below zero or less, the freezing resistance of the liquid film prepared in the invention is improved. Furthermore, ramie leaves serve as raw materials and achieve a water retention effect, so that the liquid film prepared in the invention has a water retention effect. Ramie fibers, chloroethylene and isopropanol are blended and reacted under alkaline and nitrogen protection conditions, the obtained reactant contains carboxymethyl ramie fibers, a mixture containing ethylene glycol for later use, a reactant containing etherified ramie fibers and a sodium silicate solution are mixed, hydrochloric acid is addedinto the mixed solution, and an orthosilicic acid precipitate is produced from sodium silicate under acidic conditions. Therefore, the properties of the liquid film prepared in the invention such as freezing resistance, thermal insulation and water retention property are improved, and the liquid film has wide application prospects.