The invention relates to a method and device for preparing bacterial cellulose composite materials quickly on a large scale. The method comprises the steps as follows: (1) a bacterial cellulose producing strain is inoculated in liquid medium for propagation and then transferred into a biological reactor containing framework material for perturbation cultivation, so that bacterial cellulose composite material can be obtained; and (2) bacterial cellulose of the bacterial cellulose composite material is peeled off from the framework material or the cellulose composite material is soaked in NaOH solution to be washed. The device comprises a thermometer opening, an acid liquor and alkali liquor feeding opening, a handle, an air vent, a pH meter opening, a nutrition feeding opening, a rotating shaft, a fermentation tank, a motor, a rotating drum, a fermentation tank jacket, a circulating water inlet, a circulating water outlet, a nutrient fluid inlet, a nutrient fluid outlet and a condensed water outlet. The rotating drum is fixed on the rotating shaft in the fermentation tank. The device provided by the invention has the advantages of simplicity, convenience, detachable die, low cost, high production efficiency and high degree of automation; and the obtained bacterial cellulose composite material can be widely applied.