In order to solve the problems existing in the traditional milk powder drying control system, this paper analyzed the spraydrying process of milk powered and determined a new control method. Exhaust temperature as the main controlled variable to regulate the steam valve opening coarsely; inlet air temperature as the deputy variable to regulate the steam valve opening subtly in this control method. Main controller controller using fuzzy PID controller, and deputy controller using conventional PID control. simulation model of the system is built through the MATLAB and simulation experiments proved that this system has good static and dynamic performance.