Tandem type small biogas fermentation device

The utility model discloses a tandem type small biogas fermentation device, and relates to a biogas fermentation device. An inclined channel I is formed between the feeding tank and the primary fermentation tank; the primary fermentation tank is communicated with the bottom of the buffer tank; the buffer tank and the secondary fermentation tank are provided with an inclined channel II; the secondary fermentation tank and the discharge tank are provided with an inclined channel III; the bottom of the primary fermentation tank is a landslide; skylight openings are reserved in the tops of the first-stage fermentation tank and the second-stage fermentation tank, and movable covers cover the skylight openings; biogas conduits are respectively buried and mounted; the tops of the feeding pool, the buffer pool, the discharging pool and the biogas slurry pool are all covered with steel cover plates, steel stand columns are arranged in the buffer pool, limiting plates are fixed to the steel stand columns, slide carriag