The invention relates to a muffling bucket used for a roots blower. The muffling bucket comprises a bucket body. The external wall of the bucket body is provided with an air inlet and an air outlet. The lower end of the bucket body is fixed to a pedestal. The upper end of the bucket body is connected to a bucket cover. The inner side surface of the bucket cover is fixed to muffling cotton. A plurality of fixed rods, which are abutted against the lower side surface of the muffling cotton and allows the lower side surface of the muffling cotton to be concaved to form muffling grooves, are horizontally fixed to the internal side wall of the bucket body. The upper side surface of the pedestal is fixedly connected to a guiding plate in a perpendicular manner. The guiding plate is made of ceramic composite asphalt, phenolic resin, inorganic fibre and a water reducer, and therefore when air flow enters from the air inlet, the air flow strikes the guiding plate and enters the guiding plate to convert sound into various inaudible frequencies and into heat energy to be consumed, thus weakening reflected sound. In addition, the air flow is guided by the guiding plate and strikes the muffling cotton, and noise is absorbed by the muffling cotton, so that the muffling effects are good. Accordingly, the muffling bucket used for the roots blower can adjust noise according to needs of the air flow rate, and is flexible in use and high in applicability.