Abstract: Spraying system is the core supporting equipment of the Icing wind tunnel, which is mainly used for simulating aerial environment. The investigation for the precision control method of pressure and temperature was developed, according to the complicated structure and high control accuracy of spraying system. The problem of spray rake pressure inconsistent and mutual coupling were solved, by giving pumps rotating speed, presetting inlet and outlet regulating values opening ratio, and feedback controlling outlet regulating values. Base on which, the high accuracy and wide range control of water pressure were achieved at last. Accurate water temperature control was gained through circular calefaction in seedtime and accurate temperature adjustment using variable parameter PID in test time. The problems of air pressure and temperature mutual coupling and the temperature change time delay were solved, through the method of fuzzy adaptive PID for temperature control and variable proportion coefficient PID for pressure control, and then realized the accurate air supply pressure and temperature control. Experimental results proved that the control algorithm is feasibility, and the performance of the spraying system can satisfy the technical requirements.