The invention relates to a method for preparing high-purity puerarin and daidzein at the same time. The method comprises the following steps of: mixing and extracting crushed kudzu root and ethanol in a feed liquid ratio of 1:6 to 1:10; filtering the obtained mixture, and performing vacuum concentration on the filtrate until the filtrate is dried to obtain a kudzu root extract; re-dissolving the kudzu root extract by using an ethanol solution with appropriate concentration, and then refluxing, hydrolyzing and extracting the mixture for a certain period of time by adding a hydrochloric acid solution and chloroform; standing and cooling; separating the chloroform; performing vacuum concentration; performing recrystallization on the concentrate by adopting the ethanol solution to obtain daidzein crystals; adding water to dilute acid hydrolysate; placing the mixture for 48 to 72 hours to separate out puerarin coarse crystals; and performing recrystallization on the puerarin coarse crystals by using acetic acid-methanol to obtain a puerarin product. By adopting the method, the puerarin and the daidzein in the kudzu root are extracted and separated at the same time, so that the utilization value of the kudzu root is improved, and a traditional Chinese medicinal material resource is fully used. According to the method, hydrolysis and extraction are finished at the same time, so that operation process steps are reduced, the usage amount of the solvents is reduced, the production cost is low, and the yield is high.