The extraction process and biological activity of soapberry saponin were studied in order to make better use of soapberry. The crude extract of soapberry saponin was obtained by the process of soapberry peel powder, solution suction filtration, rotary evaporation and other processes. N-butanol and other reagents were used to obtain soapberry saponin essence products through dissolution, layered extraction and rotational evaporation for crude extracts. Oleanolic acid was selected as the standard to draw a standard curve, and the saponin content, yield and purity were calculated. The saponin detergency detergency was determined by photoelectric colorimetry, the antibacterial activity was detected by the twofold dilution method of the test tube, and the antioxidant activity was tested based on the determination method of hydroxyl radical action. The experimental results showed that the purity and yield of soapberry saponin are higher under the condition of raw material powder treatment and particle size of 20-60 mesh. When the concentration of absolute ethanol solution is 70%, the yield of saponin reaches the upper limit. When the extraction ratio is 1:12, the saponin content is the highest. The decontamination and antibacterial properties of saponin solution are higher than those of saponin concentrate after fermentation. The antioxidant activity of soapberry saponins is good.