The invention discloses a method of extracting and purifying bergenin from cissus pteroclada hayata. The method comprises the steps that the cissus pteroclada hayata is smashed and screened, ethanol solution is added according to the mass-to-volume ratio of 1 to 8-20 for reflux extraction, solid-liquid separation is conducted to obtain filtrate, the filtrate is concentrated, macroporous resin is added into the concentrated solution for static adsorption, the macroporous resin subjected to adsorption is placed on a pillar, impurities are removed and elution is conducted with distilled water and ethanol solution in sequence, the eluant is collected and concentrated to obtain crude bergenin, and the crude bergenin is recrystallized with ethanol to obtain pure bergenin. According to the method, sources of raw materials are wide, price is low, production cost is low, production conditions are moderate, and pollution to the environment is light.