The invention discloses a freeze-vacuum drying protection agent for Edwardsiella tarda and a freeze-drying method thereof, belonging to the technical field of freeze-vacuum drying preservation of marine bacteria. The ingredients are: skimmed milk powder, lactose, trehalose, vitamin C, NaCl and sterile water. Under aseptic conditions, mix the live bacterial suspension of Edwardsiella tarda and the above-mentioned freeze-drying protectant solution in a volume ratio of 1:4 to 1:1, divide them into separate packages, and quickly freeze them at -80°C After 5 to 6 hours, freeze-dry for 18 hours at a vacuum degree of 0.28mbar and a freeze-drying chamber temperature of -54°C for 18 hours, then reduce the vacuum degree to 0.034mbar and continue to freeze-dry for 2 hours at a temperature of -54°C. After the freeze-drying is completed, fill the freeze-drying cabin with 99.99% dry carbon dioxide gas to standard atmospheric pressure and seal the cover. The invention establishes a technical method for long-term preservation of Edwardsiella tarda by freeze-drying and vacuum drying, and provides technical support for in-depth related research on Edwardsiella tarda.