NOVELTY - Producing methane using ultra-high-efficient fermentation system comprises taking fermentation raw material, conveying into a cylinder of a first-stage fermentation system and then conveying into a second-stage raw material tube of a second-stage fermentation system, producing biogas in the first-stage fermentation system, accumulating raw material at inlet and outlet side wall of the cylinder, forming a fermentation zone between the adjacent plate or adjacent blocking plate and the material cylinder, producing biogas in the second-stage fermentation system, and storing.    USE - The method is useful for producing methane using ultra-high-efficient fermentation system (claimed).    DETAILED DESCRIPTION - Producing methane using ultra-high-efficient fermentation system comprises (i) taking fermentation raw material, conveying into a cylinder of a first-stage fermentation system and then conveying into a second-stage raw material tube of a second-stage fermentation system, (ii) producing biogas in the first-stage fermentation system, accumulating raw material at inlet and outlet side wall of the cylinder, forming a fermentation zone between the adjacent plate or adjacent blocking plate and the material cylinder, allowing biogas liquid to flow in a first pipe and a second pipe set within first-stage raw material tube, rising the slurry in the first pipe and the second pipe, and then conveying into the second-stage raw material tube, (iii) producing biogas in the second-stage fermentation system, accumulating raw material at inlet and outlet side wall of the cylinder, forming a fermentation zone between the adjacent plate or adjacent blocking plate and the material cylinder, allowing biogas liquid to flow in two pipes set within second-stage raw material tube, flowing through a second-stage discharging pipe, drain pipe and cloth bacteria device, flowing water into the cloth bacteria device, allowing water pressure within the storage tank of biogas liquid discharging tube pipe to reach in the second-stage fermentation pipeline, and then allowing to flow into discharging pipe, (iv) storing biogas in second-stage fermentation pipe, draining slurry stored within the chamber pressure into a two-way feed tube and then by drain cloth bacteria device, returning the material into the drain pipe of second-stage fermentation pipe, maintaining the slurry liquid pressure inside the chamber to lower than the lowest point of the feeding tube, then flowing the stored slurry between the feed tube and cloth bacteria device, draining back into the second-stage fermentation pipe, maintaining pressure of slurry liquid stored at surface pressure of less than the lowest point of the drain tube, and then refluxing into the second-stage fermentation pipe, and (v) repeating the process for generating methane.