The invention discloses a silver-loaded nano-TiO2 antimicrobial preservation method of Nanfeng mandarin oranges, which comprises the following steps: preparing a high-activity inorganic nano-antibacterial agent, namely silver-loaded nano-TiO2 powder without toxicity or side effects into a preservation solution, performing film coating preservation on the surfaces of the Nanfeng mandarin oranges or placing freshly picked ripe Nanfeng mandarin oranges into the preservation solution for impregnation, getting a layer of dense protective film, and actively preventing and killing pathogenic bacteria. By adopting the method, original various nutritional ingredients in the Nanfeng mandarin oranges can be effectively preserved, original luster and flavor of the Nanfeng mandarin oranges can be kept, the Nanfeng mandarin oranges can be stored for a long time without peculiar smell, the preservation period can be further prolonged, the preservation effect of the Nanfeng mandarin oranges can be ensured, and the method is in line with the current research and development direction of novel green fruit and vegetable preservation agents. Silver-loaded nano-TiO2 has broad-spectrum antimicrobial and sterilizing functions, and can inhibit propagation and derivation of the pathogenic bacteria on the surfaces of fruit peels, realize a good antimicrobial effect, greatly reduce the rotting rate, prolong the preservation period of fruits, and further fully ensure the fruit quality of the Nanfeng mandarin oranges during the storage period.