The invention discloses a large-scale multi-level linkage biogas fermentation device. The large-scale multi-level linkage biogas fermentation device comprises a water pressure chamber, wherein a plurality of fermentation pools of the same specification are connected to the periphery of the water pressure chamber; the fermentation pools are connected with the water pressure chamber through water drainage pipes; each water drainage pipe comprises a feeding hole drainage pipe and a discharging hole drainage pipe; a feeding hole and a discharging hole are respectively formed in the left end side and the right end side of each fermentation pool; a fermentation chamber is arranged in the middle of each fermentation pool; each fermentation chamber is connected with the corresponding feeding hole and the corresponding discharging hole; a gap exists between each of the upper side surface and the lower side surface of each gas storage plate and the inner side surface of the corresponding fermentation pool; each fermentation pool also comprises a pull rod consisting of a cross rod and a vertical rod, wherein at least one end side of each cross rod is connected with the corresponding vertical rod, each cross rod is arranged in the corresponding fermentation chamber, and each vertical rod penetrates through the gap between the side surface of the corresponding gas storage plate and the corresponding fermentation pool.