The invention provides a passion fruit fresh-keeping agent, as well as a making method and application thereof, and belongs to the field of food processing. The passion fruit fresh-keeping agent is made through the following steps of firstly cutting passion fruit shells into passion fruit shell segments, cutting grapefruit peel into grapefruit peel segments, cutting orange peel into orange peel segments, adding activity fluid, and performing treatment in a superhigh-pressure homogenizing machine to obtain substances a; then crushing perilla leaves, konjak and corn stigma, soaking the crushed perilla leaves, the crushed konjak and the crushed corn stigma, and performing extraction by a subcritical extraction method to obtain substances b; and mixing the substances a with the substances b, and substances c extracted from buckwheat flowers, honeysuckle flowers, common andrographis herbs, heartleaf houttuynia herbs, radix scutellariae, folium isatidis and herba artemisiae scopariae, to obtain a mixture, putting the mixture into a high-pressure micro jet nanometer dispersion machine, and performing dispersion to obtain the fresh-keeping agent. The invention further provides a use method of the fresh-keeping agent. The obtained passion fruit fresh-keeping agent is safe and non-toxic, can prevent passion fruits from producing phenomena of weight losses, shrinkage and the like, can maintain the quality of the appearance and the pulp of the passion fruits, and can prolong the storage life of the passion fruits.