Abstract: The steam explosion was used to pretreat oil Camellia seed cake meal,and the effects of steam explosion on the extraction rate,physical and chemical properties,and internal microstructure of oil Camellia seed cake meal were investigated. The results showed that the best conditions for steam explosion pretreatment as followed:1.2 MPa,60 s. The surface tension of tea saponin after steam explosion treatment was 47.63 m/Nm,which was lower than the value of control group(48.07 m/Nm),and the difference in foamability was not significant(P<0.05). Scanning electron microscopy results indicated that surface of the oil Camellia seed cake meal after steam explosion treatment was rough and fluffy,and the original structure was destroyed,which was conducive to the release of tea saponin. Fourier transform infrared spectroscopy showed that the shape and basic position of the characteristic absorption peak was not changed,but the intensity of some peaks increased. Liquid chromatography-mass spectrometry results demonstrated that the tea saponin was mainly composed of tea saponin E₁₃,camellia saponin D₅,tea saponin B₅ or tea saponin C₁.Therefore,steam explosion pretreatment combined with alcohol extraction method could be an efficient method for extracting of tea saponin.