Method used for producing biogas by taking sugarcane leaves as raw material

The invention discloses a method used for producing biogas by taking sugarcane leaves as a raw material. The method comprises following steps: 1), sugarcane leaves are cut into pieces which are 3 to 5cm in length, a nitrogen-containing substance and water are added until carbon/nitrogen ratio reaches 20-30:1, and water content of an obtained mixture ranges from 60 to 70%, and then a fermentation microbial inoculum is added so as to obtain a mixed material, wherein the fermentation microbial inoculum accounts for 0.2 to 0.4wt% of the sugarcane leaves; 2) the mixed material is collected, and piled so as to obtain piles with a width of 1.2 to 1.5m and a height of 1.0 to 1.5m, the piles are covered with plastic thin films, and the bottoms of the piles are provided with slits for ventilation, and the plastic thin films are provided with a air hole every 30 to 50cm; 3) the temperature in the piles is increased to more than 50 DEG C, and is maintained for more than 5 days, and then the mixed material is delivered in