The invention provides an efficient and energy-saving drying system for polyaluminum chloride production. The method comprises the following steps: evaporating, concentrating and drying a polyaluminium chloride solution with the concentration of about 40% into a polyaluminium chloride solution with the concentration of about 60% by using an external circulation evaporator; drying the polyaluminiumchloride solution with the concentration of about 60% into a semi-dry solid with the concentration of about 80% by using a roller dryer; and finally, drying about the semi-dry solid with the concentration of about 80% into granular polyaluminum chloride by using an air flow drying system. The granular polyaluminium chloride does not generate dust pollution in use, and the use amount of steam is saved compared with a roller dryer no matter whether the external circulation evaporator is used for concentrating and drying or pneumatic drying, so that the use amount of the steam can be effectivelyreduced, the energy is saved, and the production cost of the solid polyaluminium chloride is reduced.