Abstract: To obtain optimal technoloy condition of microcapsule of soybean powder,soybean powder as the research object,with the stability coefficient as a measure of the embedding effect of the microcapsules. Three parameters including the amount of emulsifier,the amount of stabilizer,homogeneous pressure were independent variable,the stability coefficient was the response value,based on single factor experiment,using response surface test to optimize the above factors. The optimum operating conditions were as follows:emulsifier was sucrose fatty acid ester,stabilizer was beta-cyclodextrin,spray drying inlet and outlet temperature was 200 and 100 ℃ respectively,the addition of sucrose fatty acid ester was 24 mg/m L,beta cyclodextrin amount was16 mg/m L,the emulsification pressure 55 MPa. Under these conditions,stability coefficient was 95.53%. The micro-capsule of soybean powder had a good solubility,good water solubility and high nutritional value.