The invention discloses a defoaming device for a cellulose solution, and a defoaming method of the defoaming device. The defoaming device comprises an outer barrel, a material barrel, a speed regulation device, a liquid inlet pipe and a material storage device, wherein the outer barrel is configured into a main body of the defoaming device; a liquid outlet is formed in the bottom of the outer barrel; the material barrel is arranged in the outer barrel and is provided with a through hole; the speed regulation device is used for driving the material barrel to make centrifugal movement; the liquid inlet pipe passes through the outer barrel and feeds a solution into the material barrel; the material storage device is communicated with the liquid outlet formed in the bottom of the outer barrel,and is arranged at the position lower than the outer barrel; a discharge device is arranged at the bottom of the material storage device. The defoaming device, which is simple in structure and easy to operate, for the cellulose solution has the characteristics of being high in defoaming efficiency, realizing continuous defoaming, and guaranteeing the continuous proceeding of the subsequent spinning; material conveying is not affected by a defoaming process, and efficient defoaming and continuous production are carried out at the same time; furthermore, the defoaming method is good in effect;the defoaming device for the cellulose solution can be used for producing a spinning solution with good stability and evenness, and does not produce gel.