NOVELTY - Multi-stage fermentation system comprises the first stage and second stage fermentation system (40). The mounting position of second stage is higher than the first stage fermentation system. The first stage and second stage fermentation system are connected through pipeline. The first stage system comprises pipeline, cylinder (12) and inlet bucket. The pipeline and cylinder are separated with clapboard. The inlet bucket and outlet cylinder are separated by tube and cylinder.    USE - Multi-stage fermentation system.    ADVANTAGE - The multi-stage fermentation system promotes stirring of biogas, uniformly distribution of strain and increase efficiency of fermentation.    DETAILED DESCRIPTION - Multi-stage fermentation system comprises the first stage and second stage fermentation system. The mounting position of second stage is higher than the first stage fermentation system. The first stage and second stage fermentation system are connected through pipeline. The first stage system comprises pipeline, cylinder and inlet bucket. The pipeline and cylinder are separated with clapboard. The inlet bucket and outlet cylinder are by tube and cylinder. The pipeline of biogas fermentation liquid are provided with multi-number plate, inlet and outlet side wall, adjacent plate and cylinder, which forms a fermentation area. A gas guide feedstock tube is provided with top part of first stage pipeline and second stage fermentation system, respectively. The second stage system comprises pipeline, feedstock tube and discharging tube. The pipeline is provided at the upper part of second stage system, where the feedstock pipe is connected with drain pipe. The discharging tubes are connected horizontally. The feedstock tube and discharging tube are provided with biogas slurry to control water pressure of first stage and second system, respectively in one-way flow. The pipeline of first stage system is connected with aqueduct, which is connected with hydraulic pressure.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of multi-stage fermentation system    Cylinder (12)    Second stage fermentation system (40)    Pipeline (41)    Feedstock pipe (42)    Discharging tube (45)