Microbial fermentation tank

The invention discloses a microbial fermentation tank which structurally comprises a water pump, a driver, a fermentation tank device and an operation panel, when the fermentation tank device performs fermentation operation and liquid to be fermented is injected into a lower tank body through a tank cover mechanism, a program is set through the operation panel, the fermentation operation is performed, and the bottom end of a shaft rod of a stirring mechanism is clamped with a bearing at the upper end of a bottom shaft; when the stirring mechanism rotates to work, stirring blades enable all layers of fluid to be mixed through the existence of the speed difference of the fluid in the tank body, during mixing, the water pump conducts heat on the fluid and adjusts the temperature of fermentation liquor through the inner constant-temperature pipe and the outer constant-temperature pipe, and meanwhile an air inlet of the air inlet mechanism is connected with an external oxygen bottle; oxygen is conveyed and supplie