Vacuum lyophilizing method was used to prepare soybean protein-phosphatidyl choline emulsification powder after the ultrasonic treatment and high pressure homogenization, and the physical and chemistry characteristics of lyophilizing powder and reconstituted emulsion were determined by scanning electron microscopy, laser particle size analyzer and infrared spectrum. It was found that the reconstituted lyophilizing powder had good solubility, and the particle size of the emulsion was the same as that of the original emulsion. Scanning electron microscopy and lyophilized powder particle size distribution showed that the nanoemulsion powder prepared by high-pressure homogenization and ultrasonic had dense and uniform structure, the surface had no cracks and hole, the surface of powder prepared by high pressure homogeneous was more smooth, the particle size distribution showed unimodal distribution, the average particle size was only 6.13μm. The entrapment efficiency and yield of nanoemulsion lyophilized powder prepared by ultrasound and high pressure homogenization both were more than 90%, while the nanoemulsion lyophilized powder prepared by ultrasonic preparation was more conducive to the package of β-carotene and better prevention of the loss of β-carotene. The results of infrared spectroscopy experiments showed that the α-helix and β-fold structure of the protein powder prepared by high pressure homogenization were slightly lower. And compared with the stability and shelf life of soybean protein-phosphatidyl choline nanoemulsions, a significant increase was showed for the lyophilized powder under the same storage conditions.