In this paper, the Huainan No.1 Sewage treatment plant's dehydrated sewage sludge and the power plant fly ash have been taken as the main raw materials and clay as the cementing agent to prepare lightweight ceramsite. Using the single-factor experiment to screen roasting craft, the optimal conditions are obtained as follows: the clay content is approximately 15%, sludge content 35-40%, preheating temperature 350-400°C.The preheating time is 15-20mins, roasting temperature 1150-1200°C, roasting time 15-20mins. The product’s loose density is 710-750kg/m3, particle density 1305-1380kg/m3, compressive strength 13.2-15.2MPa, bibulous rate 12.4-18.1%, particle shape factor 1.3-1.4, specific surface area 5.68-6.01m2/g. The performance index can meet the national standard requirements for fly ash ceramsite in the light collection aggregate. This lightweight ceramsite may serve as the water treatment material, the building material and the thermal insulation material and so on. This research had not only solved the problems of contamination caused by sludge and solid wastes like fly ash, but also brought certain economic and environmental benefits.