the invention disclose a food preserve and pack method including the following steps: 1) deliver the conjoined package box with the food inside to the packing, sealing and cutting area; 2) the sealing and cutting device (2) presses on the film coating so that the film and the support device will surround the foods and forms a seal cavity; (3) the air pumper evacuates; then pumper aerates into the cavity with protective gases. 4) the sealing and cutting device (2) pressure heat seals the cavity after the aerating; 5)the fluctuating pressure device(1) cuts the package box from the film coating; 6) the deliver mechanism delivers out the sealed package box. Above process including deliver in, locate, film coating press, evacuate, aerate, heat seal, cutand deliver out all finish continuously on a single machine. Each process is controlled by control logic made up of relays or PLC. The invention not only saves the package material, lowers the cost, enhance the efficiency but greatly varies the package patterns, and the preservation is effective and environmental,