The invention discloses a fermentation device with a liquid storage tank. The fermentation device comprises a hollow tank body, a support is arranged at the bottom of the tank body, a soaking chamberis formed in the tank body, and a soaking liquid replacing device is arranged on the tank body and comprises the liquid storage tank arranged on one side of the tank body. A lifting pump is arranged on the liquid storage tank. According to the fermentation device, the liquid storage tank is arranged on one side of the fermentation tank body and can store soaking liquid in the fermentation tank body, circular flowing of the soaking liquid is achieved, contact between the soaking liquid and soaked objects, such as pickled vegetables, is enhanced, and the quality of a product is guaranteed; meanwhile, the liquid storage tank can store fresh soaking liquid, the soaking liquid in the fermentation tank body can be replaced in time when changing, it can be guaranteed that the quality of the product is not influenced, the production cost and consumed time caused by replacement of the whole soaking chamber are reduced, and large-scale and industrial production of the pickled vegetables and thelike is benefitted.