Egg yolk powder was obtained by spray-drying technology, and the powder properties were studied. On the basis of single factor test, the effects of the factors, such as spray flux, feed temperature and inlet air temperature, on the solubility of the egg yolk powder were investigated by Box-Benhnken center composite design and response surface technology. The powder properties were analyzed through its rheological property, granular structure and stability. The results show that the optimum technical conditions are as follows: spray flux of 17.37 ml/min, feed temperature of 35.65°C, inlet air temperature of 185.36°C. Under the optimum conditions, the solubility exponent is 1.8506 and the solubility is 98.74 g/100 g. Analyses show that the instant egg yolk powder is typical non-Newtonian fluid but with pseudo plastic characteristics. Moreover, the powder has intact structure and stability.compared with fresh egg the recoverability of the egg yolk powder is better.