NOVELTY - Environmental remediation of anaerobic fermentation residues for producing ecological crust comprises separating anaerobic fermentation residues of biogas project into biogas residue and biogas slurry, crushing and drying biogas residue to obtain original substrate of ecological crust, determining the pH value of the biogas residue and the amount of e.g. organic matter and microelements, stirring with nutrient substance comprising e.g. medical stone, molding substrate, providing seedling hole, paving ecological crust, sowing seeds, watering, and promoting seed germination and growth.    USE - The method is useful for environmental remediation of anaerobic fermentation residues for producing ecological crust.    ADVANTAGE - The method is environment-friendly and convenient to operate, has simple preparation process, saves resource, and is suitable for preventing and controlling desertification and restoring regional ecology.    DETAILED DESCRIPTION - Environmental remediation of anaerobic fermentation residues for producing ecological crust comprises: (a) pumping and separating anaerobic fermentation residues of biogas project into a solid-liquid separation device to obtain biogas residue as a solid fraction and biogas slurry as a liquid fraction, crushing the biogas residue with a crusher to obtain the residue powder with particle diameter of 1-5 mm, and drying the biogas residue powder in field until its moisture content is below 40% to obtain biogas residue powder as an original substrate of ecological crust; (b) determining the pH value of the biogas residue and the amount of organic matter, total nitrogen, total phosphorus, total potassium and microelements to restore materials according to the plant growth needs, adding to the biogas residue powder quantitative nutrient substance comprising medical stone (100-120 meshes) and a water retaining agent powder in a mass ratio of 200:1 for limited vegetation growth, improving the microelement content and water retaining properties of the substrate, stirring uniformly in a stirring device at 10 revolutions/minute, during the stirring process adding ammonia or phosphoric acid to adjust the pH value of the original substrate to 5-7, stacking for 3-6 days, and quenching and tempering; (c) pressing the prepared substrate in a mold for forming crust of bulk density 1.1 g/cm3 and thickness of 5 cm, independently cropping the shape based on the site conditions, and providing a conical shaped seedling hole on the rough crust surface, where the seedling hole size depends on the amount of seed; and (d) restoring vegetation, collecting target recovering seed in advance, selecting good seeds, paving ecological crust independently in different environmental habitats during seed germination period, placing 4-8 seeds in each crust seedling hole, watering, and promoting seed germination and growth.