In this study, the combustion emission characteristics of pyrolysis oil and gas from raw sewage (SC-Raw), sewage with KOH activation (SC-KOH) and sewage with ZnCl2 activation (SC-ZnCl2) were analyzed and compared. The results indicated that the three kinds of sludge samples have the same pollutant release patterns following the combustion of corresponding pyrolysis oils and gases with oxygen-enriched air. CO2, SO2, NOx, N2O and HCl are the main pollutants, while CO, NH3, HCN and CH5N accounted for a minor relative proportion. Compared to SC-Raw, SC-KOH and SC-ZnCl2 can be effective in reducing acid gases, and most significantly the removal of SO2. Likewise, the pyrolysis process shows that more N2O is released from SC-KOH, while SC-ZnCl2 releases a considerate amount of HCl.