A mathematical model for spinning processing parameters and NH3 emission is established using uniform design and quadratic polynomial regression. And principal-factor effect, single-factor effect, marginal effect and double-factor effect of the model were analyzed. The result showed according to the contribution rate, NH3 emission in cigarette mainstream smoke was most greatly effected by open degree of the door of the hot air, followed by HT operating steam pressure, the temperature of cylinder wall, hot-air temperature, the revolving speed of casing cylinder and tobacco cut width, among which tobacco width was not significantly effected. The NH3 emission exhibit a negative correlation with HT operating steam pressure and the temperature of cylinder wall, whereas a positive correlation with hot air damper opening, hot-air temperature and the revolving speed of casing cylinder. Strong interactive influence existed between HT operating steam pressure and hot-air temperature, between HT operating steam pressure and the temperature of cylinder wall. Reducing the hot air damper opening, air temperature, or improving HT operating steam pressure, the temperature of cylinder wall will help to control the NH3 emission in mainstream cigarette smoke.