Discharge of sludge from water works into waters will result in the increased deterioration of water environment. Therefore, an experimental study was conducted on the addition of conditioning agent to improve sludge dewatering performance. The result shows that coagulation is inadaptable to the treatment of sludge from water works and use of powdered coal ash from power plant as conditioning agent can greatly reduce the specific resistance of sludge and the dewatering performance can be improved. The optimal dosage of fine powdered coal is 20g/100mL and coarse powdered coal is 30g/100mL. Powdered coal is mixed with sludge to form filter cake, which is blended with coal in certain proportion to make into fuel. So that incineration of sludge from water works can be realized.