The invention provides a 
biomass processing method. 
Ammonia water is adopted in preprocessing of 
biomass raw materials for separating 
lignin from 
cellulose and 
hemicellulose, and a certain amount of environmentally-friendly auxiliary agents is added to increase the removal rate of the 
lignin and enhance the subsequent conversion efficiency of an obtained 
solid substrate. The preprocessed 
solid substrate is rich in the 
cellulose and the 
hemicellulose, and can be hydrolyzed to monosaccharides and used for the 
fermentation of ethyl 
alcohol and other products. A preprocessing liquid obtained by the method is rich in 
lignin degradation products and a small amount of 
hemicellulose degradation products, and the 
lignin degradation products and the hemicellulose degradation products can be recycledby acid 
precipitation, 
centrifugation or membrane separation and other techniques. Most of the 
ammonia water and the auxiliary agents used in the preprocessing are in the preprocessing liquid, can beseparated by waste steam 
recovery, reduced pressure 
distillation and other methods, and can be reused for 
biomass preprocessing. By adopting the preprocessing method, the preprocessing effect of theammonia water on biomass is obviously improved by the addition of the small amount of low-cost auxiliary agents, and the preprocessing method has a relatively good application prospect.