The invention belongs to the field of cephalosporin medicinal preparations, especially relates to a flomoxef sodium lipidosome freeze-drying preparation and a preparation method thereof. Flomoxef sodium, buffer salt, an excipient, neutral phospholipids, a stabilizer and cholesterol in specific weight ratio can be made into flomoxef sodium lyophilized liposome preparation with excellent quality. The active component of flomoxef sodium has high encapsulation, and the liposomes have small particle size and uniform distribution. Compared with the flomoxef sodium all in the dosage form of sterile lyophilized powder injection in the market, the flomoxef sodium liposome preparation has better stability, long-term storage, and significantly improved curative effect. The preparation method of the liposome uses conventional process equipment, is low in production cost, applicable to industrial-scale production, and high in production efficiency.