Abstract: The effect of reaction parameters on spray-drying of yolk immunoglobulin-rich egg powder were conducted to explore by single factor experiments and orthogonal experiment with activity assays of IgY (yolk immunoglobulin) and yield of egg powder as antigens.The optimal spray-drying conditions were obtained as follows:the feed flow rate was 500mL/h, the concentration of egg liquid was 20% and the inlet air temperature was 160℃.Under those conditions, the yield of egg powder was 16.23% and the activity assays of IgY was 92.60%.In addition, the inlet air temperature had the largest impact on the yield of egg powder followed by concentration of egg liquid and feed flow rate.