Closed-cycle spray drying equipment is a closed-loop spray drying process for products made from organic solvents such as ethanol, acetone, ethane, gasoline, etc., and using inert gas (or nitrogen) as the drying medium. The system uses inert gas as the circulating gas, which has a protective effect on the dry materials. The circulating gas undergoes the process of moisture carrying and dehumidification, and the medium can be reused. The products in the whole process are non-oxidized, the medium can be recovered, and the inert gas (or nitrogen) can be recycled. At the same time, the whole set of equipment adopts explosion-proof design to ensure the safety and environmental protection of the drying process. This series of spray drying equipment is often used for spray drying of precision ceramics, pharmaceuticals, battery materials, cemented carbide (WC.Fe) powder, etc.