Soybean isoflavones were extracted from soybean waste by ethanol-aqueous solution, and after preliminary purification, a gradient elution was performed with AB-8 macroporous adsorption resin to obtain a high purity of gensein isoflavin-like liquid. The samples were determined and compared by thin layer chromatography, ultraviolet spectrophotometry and high performance liquid chromatography. The results show that the thin layer chromatography method is simple and the separation effect is good. The standard curve was plotted by UV spectrophotometry to calculate the sample concentration. This method has high accuracy, high precision and good reproducibility. The relative mean deviation RSD of the spiked recovery experiment was 3.1%, the relative average deviation of the precision experiment was 04.0%, and the relative average deviation of the repeatability experiment was 24.0%. High performance liquid chromatography has the advantages of high resolution and sensitivity, and the purity of the sample is 09.90%