Abstract: In order to solve the problems of sludge drying, the working principle and system structure of sludge drying-system by solar energy and heat pump were introduced firstly, and then the main equipment of this system was calculated and designed, the system performance was analyzed comprehensively through experiment. Finally the energy efficiency and economy of solar energy heat pump drying-system were compared with that of the other drying system. The results showed that this system was energy-saving, eco-friendly and economy. Equipped with solar thermal collector, the system can save energy about 10% in average. The research can provide a reference for engineering application of sludge drying by solar energy and heat pump.