Abstract: To investigate the catalytic pyrolysis characteristics of dewatered municipal sewage sludge, the pyrolysis experiments were conducted using CaO, ZnCl2, K2CO3 as catalysts by the methods of thermogravimetry (TG) and Differential scanning calorimeter (DSC). The results showed that the pyrolysis process of dried sewage sludge was divided into three phases: moisture loss, volatile matter loss and fixed carbon loss for all sludge samples. The pyrolysis rate was greatly enhanced during the fixed carbon loss and the activation energy and pre-exponential factor decreased for the sludge sample with addition of catalyst. The catalytic activity of CaO were best among three catalysts.