The invention discloses a preparation method of a degradable medical infusion bag material, which belongs to the technical field of the preparation of medical materials. The preparation method comprises the following steps: stirring and gelatinizing corn starch, sterile water and salicylic acid, then adding amino acid, lactic acid and triethylamine, heating and stirring to perform the reaction, cooling, discharging, freezing, collecting frozen articles, mixing the collected frozen articles with polyglycolic acid, polyurethane, tea polyphenol and the like, collecting a mixture, granulating, performing film blowing and forming for the particles, thus obtaining the degradable medical infusion bag material. The prepared medical infusion bag material is high in degradability, pollution-free to the environment, good in material air tightness, capable of well blocking oxygen, relatively good in mechanical performance, excellent in puncture resistance, and wide in application range.