The invention discloses a polylactic resin covering material for inhibiting water evaporation in arid and semi-arid regions, and a using method of the polylactic resin covering material. The coveringmaterial is prepared from the main raw materials of water-soluble polylactic resin, a certain amount of water-soluble chemical fertilizer is added, in farmland use, the polylactic resin covering material has the function of preventing evaporation and has the efficacy of fertilization, the double benefits are achieved, and the using cost and amount of the fertilizer are effectively decreased; the configured covering material is dissolved in water, an aqueous solution with the mass percentage concentration being 0.4-0.9% is prepared and evenly sprinkled on the surface of a farmland, a three-dimensional mesh cross-linking layer is formed on the surface of the farmland, the efficacy of preventing water evaporation is achieved, the efficacy of fertilization is also achieved, the construction cost of the farmland is saved, and the using efficacy of the fertilizer is improved; and adopted high molecular materials and other raw materials are both environment-friendly materials and can be fullydegraded into non-toxic and harmless small molecular materials within 8-12 months, safety and environment friendliness are achieved, and harm to the environment is avoided.