Method for preparing nano microcrystalline cellulose from wood ear residues

The invention relates to a method for preparing nano microcrystalline cellulose by using wood ear residues, which comprises the following steps of: 1, soaking waste wood ear residues, conducting cooking at high temperature, conducting washing with water to remove surface impurities, conducting drying, conducting grinding to form fungus residue powder, conducting soaking in a mixed solvent of toluene and ethanol to remove organic matter, carrying out suction filtration, and conducting drying to obtain a clean fungus residue raw material; 2, uniformly mixing the fungus residue raw material with a NaOH solution, removing hemicellulose, and performing suction filtration and drying to obtain mushroom dreg coarse cellulose; 3, uniformly mixing the mushroom dreg coarse cellulose with a NaClO2 solution, adjusting the pH value of the solution with acetic acid, conducting treating in a water bath kettle to remove lignin, and performing suction filtration and drying to obtain fungus residue cellulose; 4, performing acid