NOVELTY - Conversion of domestic green waste into renewable energy comprises: adding domestic waste crop straw, waste clothes, cotton waste plastic and/or waste paper and green solvents e.g. methanol, ethanol, acetone and/or water into a reaction kettle and reacting; performing solid and liquid separation and recycling the solvent to obtain the green bioethanol, subjecting the remaining solid tail product to anaerobic fermentation for producing biogas at normal temperature, or using alcohol enzyme for saccharification and fermentation; adding citric acid buffer solution into the substrate and reacting.    USE - The method is useful for conversion of domestic green waste into renewable energy.    ADVANTAGE - The method yields more than 70% of bioethanol, increases production rate of more than 42.5%, achieves recycling of domestic waste, and is harmless.    DETAILED DESCRIPTION - Conversion of domestic green waste into renewable energy comprises: adding the domestic waste crop straw, waste clothes, cotton waste plastic and/or waste paper and green solvents (80-20%) e.g. methanol, ethanol, acetone and/or water into a reaction kettle and reacting at 200- 325 degrees C with a pressure of 2.3-8.9 MPa for 10-60 minutes; where the mass ratio of the domestic waste and green solvent is 1:(5-20); after finishing reaction, performing solid and liquid separation and recycling the solvent to obtain the green bioethanol, subjecting the remaining solid tail product to anaerobic fermentation for producing biogas at normal temperature, or using alcohol enzyme for saccharification and fermentation method to produce bioethanol; adding citric acid buffer solution (pH 5) into the substrate (citric acid buffer solution accounts for 6% of the solid tail product, and the dosage mass ratio of the alcohol enzyme for solid tail product is 0.5-5%), controlling the fermentation temperature at 50 degrees C for 12-72 hours to obtain the bioethanol, where the citric acid buffer solution is prepared by: dissolving citric acid (4.21 g) and sodium citrate (8.91 g) in water and making upto 1l.