The invention discloses a method for fast separating, identifying and storing sweet potato sclerotium rolfsii.The method comprises the following steps that 1, a PDA medium plate is inoculated with hyphae or sclerotia selected from a disease sample of the sweet potato sclerotium rolfsii and placed at the temperature of 20 DEG C to 30 DEG C for culture; 2, after new hyphae grow out of the PDA medium plate, new hyphae are selected and placed on a new PDA medium plate for purifying culture; 3, after purified strains are cultured for 2 d to 4 d at the temperature of 20 DEG C to 40 DEG C, a healthy sweet potato stem branch is inoculated with hypha blocks as inocula, PDA blocks are adopted as blank control, culture is carried out for 1-3 days under the sealing condition at the temperature of 20 DEG C to 30 DEG C, and when the phenomenon that the stem branch rots occurs, the sweet potato sclerotium rolfsii is confirmed; 4, sclerotium culture is carried out on the sweet potato sclerotium rolfsii, and then sclerotia are dried and stored.According to the method, the process of fast separating, identifying and storing the strains of the sweet potato sclerotium rolfsii can be simple, the workload is small, efficiency is high, and the preserved strains are easy to manage and long in survival time and can survive for 4 years or longer.