The lysozyme in egg white was purified by cation exchange-ultrafiltration， and the purification conditions and enzymatic properties of lysozyme were studied by single factor experiment and Box-Behnken experiment， and its enzymatic properties were discussed. The results showed that when the resin accounts for 24.2% of the volume of egg white solution， NaCl concentration was 1.00 mol/L， the egg white solution pH value of 9.10， the elution time of 62.61 min， it could produce lysozyme with the purity of 96.36% and the activity of 23 718.61 U/mg. The studies of the enzymological properties of lysozyme indicated that it had the highest enzyme activity when pH value was 7.0 and temperature was 60 ℃. In the pH value of 4 to 7， the activity of lysozyme could be well maintained. The thermal stability of lysozyme was good at low temperature while the activity decreased rapidly at a higher temperature. Na+ and Ca2+ had a strong activation effect while K+ had a certain activation on the lysozyme， Mg2+ and Mn2+ had little effects on the lysozyme， Zn2+ had a significant inhibitory effect on the lysozyme. Glycerol， Tween20， Tween40， Tween80 and other surfactants all had inhibitory effect on lysozyme while glycerol had the strongest inhibitory effect. The research results had important value and significance for the industrial purification and production of lysozyme.