The invention discloses a metschnikowia fructicola strain BY33, which is wide in antibacterial spectrum and stable in effects, for preventing and controlling postharvest diseases of fruits and vegetables, and a using method and use of the metschnikowia fructicola strain BY33. The strain is preserved in China General Microbiological Culture Collection Center (CGMCC), and has a preservation number of CGMCC No. 14908. The using method of the metschnikowia fructicola comprises the following steps: activating a strain, carrying out fermentation culture on the strain with YPD, centrifuging, and preparing thallus into 1*10<8> cells/mL bacterial suspension with sterile water; putting fruits and vegetables such as apples, pears, grapes, strawberries, citrus or cherry tomatoes into the bacterial suspension, soaking for 30s and then taking out, and drying in the air; putting the dried products into preservation boxes, and storing at room temperature. The metschnikowia fructicola strain can be used for controlling apple penicillium, gray mold and black spot, pear fruit penicillium and gray mold, grape gray mold, aspergillosis, fusarium mildew and anthracnose, strawberry gray mold and aspergillosis, citrus penicillium as well as cherry tomato gray mold and aspergillosis at the same time, and reduces the loss caused by the postharvest diseases, thus having a very good application prospect.