The invention relates to a method for producing levan through fermentation in a fed-batch and sectional material supplementing mode, which comprises the implementation steps that: (1) the spore bacterium suspension is prepared; (2) the spore bacterium suspension is used for being inoculated into the sterilized liquid seed culture medium, and liquid seeds are obtained; (3) the liquid seeds are used for being inoculated into a sterilized 5L fermentation tank and is inoculated into the cooled fermentation tank culture medium according to the inoculation quality with the volume percentage being 5 to 12, the fermentation temperature is 30 to 40 DEG C, and the dissolved oxygen is controlled to be 30 to 40 percent; (4) after the fermentation for 10 to 15h, cane sugar with the concentration being 30 percent to 50 percent is continuously fed at the uniform speed of 1.67 ml/min; or the materials are supplemented in subsections, and the fermentation time is 24 to 36h; and (5) after the fermentation is completed, the fermentation liquid is centrifuged for 15min at 6000 r/min, thalli are removed, the supernatant fluid is taken to pass a Dalton ultrafiltration membrane with the molecular weight being 6000 to 8000, intercept liquid is concentrated into spray powder, and the levan with the yield being 200 to 600g is obtained. The method has the advantages that the process is simple, the cost is low, and the effect is very obvious.