NOVELTY - Comprehensive utilization of lignocellulosic biomass comprises crushing biomass, carrying out catalytic reaction of formic acid and acetic acid using hydrogen peroxide; evaporating liquid to obtain formic acid and acetic acid concentrated solution; adding organic solvent, carrying out solid-liquid separation; diluting separated solid, carrying out solid-liquid separation, washing with water obtained solid to obtain lignin; and decoloring liquid using activated carbon, filtering, concentrating and crystallizing to obtain xylose.    USE - Method for comprehensive utilizing lignocellulosic biomass (claimed).    ADVANTAGE - The lignin extraction rate is more than 75%, extraction rate of xylose is more than 65%.    DETAILED DESCRIPTION - Comprehensive utilization of lignocellulosic biomass raw material comprises:    (A) crushing biomass raw material, carrying out catalytic reaction of formic acid and acetic acid using hydrogen peroxide, in organic acid solution, where solid-liquid mass ratio is 1:5-1:15, controlling steaming temperature at 100-130 degrees C, reacting for 30-90 minutes, carrying out solid-liquid separation, using organic acid solution at total acid concentration of 65-90%, where acetic acid and formic acid ratio is 15:1-1:1, hydrogen peroxide biomass is 1-8%, and balance water;    (B) collecting first separated solid, carrying out catalytic oxidation of formic acid and acetic acid using hydrogen peroxide in mixed acid and solid, where solid-liquid mass ratio is 1:4-1:10, controlling pickling temperature at 20-100 degrees C, carrying out solid-liquid separation, where hydrogen peroxide is 1-8%, mixed acid solution total acid concentration is 60-90%, mass ratio of acetic acid and formic acid is 8:1-1:1, and balance water;    (C) collecting second solid obtained by solid-liquid separation, water washing at 25-100 degrees C, where pulp concentration is 4-6%, and carrying out third solid-liquid separation;    (D) collecting third obtained solid, filtering to obtain slurry;    (E) collecting liquid from first and second solid-liquid separation, evaporating at conditions of 80-140 degrees C and 200-700 kPa to obtain formic acid and acetic acid concentrated solution with solid content of 60-80 wt.%;    (F) adding organic solvent to concentrated liquid, adding, stirring, carrying out fourth solid-liquid separation, where organic solvent is 2-5%;    (G) diluting with water separated solid, carrying out fifth solid-liquid separation, washing with water obtained solid to obtain lignin; and    (H) decoloring liquid using activated carbon, filtering, concentrating, crystallizing to obtain xylose.    DESCRIPTION OF DRAWING(S) - The drawing shows a process flow chart of comprehensive utilization of lignocellulosic biomass (Drawing includes non-English language text).