In order to investigate the microwave pyrolysis characteristics of sewage sludge under different pyrolysis conditions, effect of microwave power, sewage sludge moisture content and microwave absorbing material content on the sewage sludge pyrolysis process and the pyrolysis residues was investigated. The microwave pyrolysis conditions of sewage sludge were optimized using response surface methodology and the components of pyrolysis residue were analyzed. The predicted highest pyrolysis efficiency of sewage sludge obtained from the response surface methodology was 77.4% when microwave power was 1 880 W, sludge moisture content was 79.7% and microwave absorbing materials content was 0.48 g. For comparison, the actual measurement one was 77.5%.Ash and fixed carbon accounted for a large proportion of the pyrolysis residues and the major inorganic components were SiO₂, Al₂O₃, Fe₂O₃ and CaO, etc.