The invention discloses a saturated steam catalytic burner used for a cement decomposition furnace. The burner comprises an inner sleeve, a saturated steam channel, a catalyst tank, a conical chamfer and cyclone wind wings; the catalyst tank is connected with the saturated steam channel which is connected with the inner sleeve; and the outlet end of the inner sleeve is provided with the conical chamfer and the cyclone wind wings; saturated steam enters the saturated steam channel through the catalyst tank; coal air enters the inner sleeve from the inlet end of the inner sleeve, after the coal air is mixed with the saturated steam coming from the saturated steam channel at the variable-diameter position of the inner sleeve, the diffusion degree of coal powder is increased through the conical chamfer; meanwhile, by means of the cyclone wind wings, the coal powder and the saturated steam rotationally enter the decomposition furnace; and a backflow area is formed at the end portion of a coal pipe, and the purpose of generating CO and H2 is achieved. The saturated steam catalytic burner reduces the generation amount of fuel type nitrogen oxides, reduction components generated after the saturated steam is added can reduce more generated NOx, and the sewage charge and the running cost of a whole cement factory are reduced.