Abstract: Sewage sludge and coal slime were collected from sewage treatment plant and coal washing plant in the same area, respectively. The effects of combustion temperature, combustion time and mixing ratio on the migration and transformation characteristics of arsenic （As）, selenium （Se） and lead （Pb） during co-combustion of sewage sludge with coal slime were investigated by a temperature-programmed tubular furnace and a sequential chemical extraction method. In addition, two acid leaching methods were used to investigate the environmental effects of As, Se and Pb in the combustion products of sewage sludge and coal slime. The release ratios of As, Se and Pb in sewage sludge and coal slime increased with the increase of combustion temperature and the final release ratio order is Se > As > Pb. Moreover, the release ratios of As, Se and Pb increase with the increase of sewage sludge mixing ratio. The release ratios of As, Se and Pb in sewage sludge and coal slime increase rapidly with the combustion time and then tend to be stable. The time required to reach the maximum release ratio is Pb > As > Se from high to low. Under the constant temperature combustion conditions, the release rates of As, Se and Pb in sewage sludge and coal slime at 1 200 ℃ are faster than those at 900 ℃, and the release rates of As, Se and Pb in coal slime at the initial stage of combustion are slightly faster than that of sewage sludge. The speciation distribution characteristics of As, Se and Pb in sewage sludge and coal slime are the main factors affecting the release behavior. As, Se and Pb in sewage sludge and coal slime mainly exist in inorganic bound states, and the proportions of inorganic bound As, Se and Pb in sewage sludge are higher than those in coal slime. Organic bound state As, Se and Pb in sewage sludge and coal slime are mainly released together with volatile matter when the combustion temperature is below 500 ℃. In the combustion temperature range of 800 ℃ to 1200 ℃, the content of carbonate + sulfate + oxide and sulfide bonded As in sewage sludge and coal slime is significantly reduced. The main release temperature ranges of carbonate + sulfate + oxide and sulfide bonded Pb is slightly delayed to 900 ℃ and 1 200 ℃, respectively. In the acid leaching environment, the leaching ratios of Se in the sewage sludge and coal slime combustion products are the highest, which are in the medium risk area. However, the leaching ratios of Pb are the lowest, which are basically in the low risk area.