This research in high pressure homogeneous technology preparation of soybean protein - phosphatidyl choline nano emulsion， and the soybean protein - phosphatidyl choline nano emulsion properties and stability test analysis， soy protein was determined by the single factor response surface optimization - phosphatidyl choline compound into a stable nanometer emulsion， the optimal ratio of： soy protein 1.5%， soybean phosphatidyl choline content 0.22%， high pressure homogeneous pressure 100 MPa， the conditions of soybean protein - phosphatidyl choline average particle size of 217.43 nm nano emulsion， TSI is 3.02， emulsifying production rate was 93.35%.