System for preparing methanol from energy plants and agricultural and forestry wastes and working method thereof

According to the system for preparing methyl alcohol through cooperation of the energy plants and the forestry and agricultural residues and the working method of the system, the energy plants serve as the core of raw materials and cooperate with the forestry and agricultural residues and other organic fertilizer waste, produced commodities are methyl alcohol, electric power, organic fertilizer, pure oxygen and substances in the system, and energy utilization achieves the highest efficiency through mutual cooperation of all subsystems. The anaerobic fermentation device is respectively connected with the biogas slurry storage device, the organic fertilizer production device and the biogas purification device; the biogas purification device is respectively connected with the methane reforming device and the methanol synthesis device II; the methanol synthesis device II is connected with the methanol condensation device; the methane reforming device is connected with the methanol synthesis device I; the methanol