The invention discloses a continuous crystallization device and method for spheroidization of large-particle ammonium perchlorate, and belongs to the technical field of preparation processes of propellants of rockets, missiles and the like. Ammonium perchlorate is a common oxidizing agent. The continuous crystallization device comprises a crystallizer, a material circulating pump, a refined solution raw material tank, a crystallization heat exchanger, a mother liquor overflow tank, a filter, a vacuum pump and a control device. A hot ammonium perchlorate solution is subjected to continuous feeding and continuous discharging, and a product with uniform particle and qualified quality is produced. Continuous crystallization and continuous centrifugal separation processes of ammonium perchlorate are established, manual operation is reduced, and production efficiency of the product is improved; the device and the method are particularly applicable to continuous crystallization preparation ofammonium perchlorate.