Abstract: In this paper, the necessity of designing the control system of the spray nozzle is put forward by analyzing the problems of the precise application techniques. Firstly, the design scheme of the system was analyzed and illustrated. And then, some related experiments were carried out in order to verify the design. The related calculation and experimental analysis showed as follows: according to the maximum flow rate (4 L/min), the pipe diameter was selected as 15 mm by referencing tube standards. The minimum opening of the control valve was 18.4 %, the maximum was 86.5 %, the actual adjustable ratio was 707. The max pressure measurement error was 2 %, the average error was 1.1 %, the pressure correction value was selected as 0.01 MPa, the max flow measurement error was 2.4 %, the average error was 1.2 %. After the error correction, the system could meet the requirements of the precision spraying.