NOVELTY - Tower-type system comprises a first-stage fermentation system and a second-stage fermentation system, where the mounting position of the second-stage fermentation system is higher than that of the first-stage fermentation system. The first-stage fermentation system is connected with the second-stage fermentation system through a water guide pipe. The first-stage fermentation system comprises a fermentation pipeline and a barrel outlet, where the barrel outlet is inserted on the primary fermentation pipeline to match the opening.    USE - The tower-type system is useful for promoting uniform distribution of strains by virtue of two-stage linkage fermentation (claimed).    ADVANTAGE - In the tower-type system, the fermentation route is long, the synchronous fermentation of the first-stage fermentation system and the second-stage fermentation system promotes the circular flowing of biogas slurry inside the systems so that the stirring of the biogas slurry is effectively promoted, the uniform distribution of the strains are also driven, and the fermentation efficiency within the systems is increased.    DETAILED DESCRIPTION - Tower-type system comprises a first-stage fermentation system and a second-stage fermentation system, where the mounting position of the second-stage fermentation system is higher than that of the first-stage fermentation system. The first-stage fermentation system is connected with the second-stage fermentation system through a water guide pipe. The first-stage fermentation system comprises a fermentation pipeline and a barrel outlet, where the barrel outlet is inserted on the primary fermentation pipeline to match the opening, where a fermentation pipe extends into the barrel outlet and separates into first fermentation pipe partitions, and the barrel outlet is separated into first inlet cylinder and first barrel outlet. The barrel outlet sidewall extends into the primary fermentation liquid slurry pipe; and the primary fermentation gas pipe is provided with multiple retaining plates. A fermentation area is formed between the barrel outlet side wall and adjacent block air board. The primary fermentation pipelines in each fermentation areas are connected to separate airway. The second-stage fermentation system comprises second fermentation pipe, second feed tube, second discharge tube and pressure rooms, where the end of the second fermentation pipe is connected to side of the second feed tube and second discharge tube. The secondary feed tube and the primary feeding tube are inserted into secondary fermentation pipe, and the secondary feeding tube side walls are connected to the secondary discharge pipe liquid slurry pipe for secondary fermentation. A first water guide pipe is connected between the primary feeding tube and the secondary fermentation pipe; a second water guide pipe is connected between the first fermentation pipe and second discharge pipe. The first aqueduct and second aqueduct are provided with a control system for controlling the biogas-way inside the fermentation tubes, and check valve for inflow via secondary fermentation pipeline. A third water guide pipe is set between the pressure room side and the primary fermentation pipe, and the third water guide pipe is provided with a one-way control valve for slurry flows between the primary fermentation pipelines.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of the tower-type system.