The invention relates to a method for preserving fresh walnut fruit, aiming at solving the problems that oxidation, rancidity, molding, sprouting, dehydration and the like of fresh walnut fruit are easy to occur when the fresh walnut fruit are preserved. The method mainly comprises the following steps: selecting complete fruits, soaking in calcium chloride in a refrigeration house, fumigating with thiabendazole, leaving the fruit to stand, sealing, packaging in vacuum, storing, delivering, and the like, thereby achieving preservation of the fresh walnut fruit. As the walnut fruit is sealed and packaged under an anaerobic condition, the green peel of walnuts can be prevented from being softened, the fresh walnuts are prevented from rot or metamorphism, the water content of the fresh walnut fruit is kept, the change velocities of grease acid values and peroxidation values are reduced, the generation of malondialdehyde is inhibited, the iodine value can be relatively well maintained, the good quality is maintained, the brown stain index of the green peel of the fresh walnut fruit after being preserved for 120 days is 0.13, the complete fruit rate is more than 95%, and the preserved fresh walnut fruit is all good in color, fragrance, taste and shape.