This paper deals with the co-combustion of dyeing sludge and bituminous coal by means of TGA-FTIR.The results show that ( 1) the co-combustion process mainly consists of three stages respectively corresponding to the de-volatilization and combustion of fiber materials at 150 ～ 350 ℃,the combustion of high-molecule polymer materials like bacterium protein at 350 ～ 500℃ and the calcining of inorganic mineral substancesin the dyestuff above 500℃; ( 2) the addition of dyeing sludge in bituminous coalpromotes the ignition,and a sludge dosage of 30% may result in an ignition temperature decrement of 20℃as well as a reduced general combustion parameter; ( 3) the apparent activation energy in the initial combustion stage of the sludge is only 70 kJ /mol and then increases to 130 ～ 160 kJ /mol in the later stage; ( 4) with the increase of sludge dosage,the apparent activation energy of the blend decreases in the initial combustion stage while increases in the later stage; and ( 5) comprehensively,the sludge dosage less than 20% only slightly influences the whole combustion process.Moreover,TGA-FTIR results indicate that ( 1) the mineral substances influence the pollutant emission process in blends via multiple reactions; ( 2) the alkali oxides and Fe₂O₃ in the dyeing sludge both benefit the fixation of sulphur in the ash; ( 3) NO_x mainly comes from the fuel; and ( 4) as the sludge is easy to de-volatilize,a reducing atmosphere consisting of smallmolecule combustible gases may form,which helps to suppress the generation of NO_x blends in the initial combustion stage.