A method for using biomass to produce cellulose, lignin and wood sugar comprises that breaking and screening the biomass, using low-boiling-point organic acid to immerge to decompose the biomass into wood sugar and oligosaccharide, and fluidize the cellulose and lignin, cools the liquid biomass after reaction, adds organic solvent, mixes uniformly and lays, after deposits completely, separating deposits and washes, dries to obtain non-shaped cellulose, distills the mother liquid of cellulose, recycles organic acid and generated volatile organics, distills mother liquid, cools and lays until complete deposition, separates deposits, washes, and dries to obtain wood sugar and oligosaccharide, evaporates to recycle the wood sugar and the organic solvent of deposited mother liquid, then separates the deposits, and dries to obtain lignin. The invention can completely circulate organic acid and organic solvent without waste discharged.