The invention relates to a method for extraction separation of bergenin from Rodgersia podophylla. Specifically, the steps includes: (1) sending the dry powder of Rodgersia podophylla raw material into a subcritical ultrasonic extractor to undergo ultrasonic countercurrent extraction, conducting filtration and separation, and concentrating the ethanol-containing extracted solution by a concentration evaporator to obtain an extract thick paste, and then moving to the crystallization section; (2) subjecting the waste residue obtained by extraction and filtering to heating, vacuum pumping and desolventizing in an extraction device to obtain a by-product; (3) recycling the solvents obtained by evaporation desolventizing; (4) recovering the steam condensate and returning it to a boiler plant for recycling; and (5) adding water into the extract thick paste to undergo dissolution, adding a crystallization promoter to obtain a crystallized product, i.e. a bergenin crude product, then employing 95% ethanol to perform heating dissolving, carrying out activated carbon decolorization, subjecting the filtrate to concentration under a reduced pressure to a thick state, conducting standing crystallization, and performing centrifugal filtration the next day, thus obtaining a crystallized substance, i.e. a bergenin fine product. The method provided by the invention adopts a subcritical ultrasonic extraction technology and is carried out at 40-50DEG C, the raw material fineness requirement is loosened, the operation is easy to control, crystallization is thorough, and the product yield is high.