The transfer of Zn, Pb, Cu, Mn, and Cd in ssewage sludge (SS) into flue gas was investigated through the separate combustion of SS. The transfer behaviour of the targeted heavy metals(HMs) element was expressed as a transfer coefficient (TC). Special attention is directed to the influence of burning temperature, moisture content of SS, and chlorine content on HMs transferring. Without chlorine addition, as the combustion temperature and moisture content of SS were increased, the volatilities of the five target HMs exhibit different trends. Particularly, a higher of moisture content was found to be helpful to reduce the Transfer of HMs into flue gas, such as Cd, Zn, and Pb with high volatility. The added chlorine during separate combustion of wet SS could promote to different extent release of HMs into flue gas.