The invention discloses a descending bed, which comprises a hearth, a material cabin, a material distributor and an air inlet pipe, wherein the material cabin is arranged above the hearth and is used for injecting the materials into the hearth; the material distributor is arranged in the hearth and comprises a tubular part in vertical arrangement; the top of the tubular part is sealed; a plurality of air outlet openings in separated distribution in the peripheral direction and/or axial direction of the tubular part are formed in the tubular part; one end of the air inlet pipe is positioned outside the hearth; the other end of the air inlet pipe penetrates into the hearth and communicates with the inside of the tubular part so as to supply air to the inside of the tubular part; gas supplied to the inside of the tubular part is blown into the hearth through the plurality of air outlet openings for scattering the materials. The descending bed has the advantages that the application range is wide; the material distribution uniformity is good; the structure is simple; the control is flexible.