Abstract: A dehydrating and sterilizing system includes an operating chamber, a vacuum pump unit, a microwave source and a plasma source. The operating chamber is used to contain food products, and is connected with the vacuum pump unit that can discharge air from the operating chamber for vacuum-dehydrating operation. The microwave source communicates with the operating chamber for a microwave processing procedure. The plasma source further communicates with the operating chamber for a plasma processing procedure. The method includes the steps of: pretreating operation; vacuuming operation; microwave-dehydrating operation; and plasma-sterilizing operation.