A swing, automatic variables and greenhouse mist sprayer equipped with the sprinkler swing function and automatic dosing and discharge liquid system was presented. In order to verify and optimize pesticide application efficiency of mist sprayer, parameters such as spraying flow rate，spraying distance, sprinkler swing speed and sprayer forward velocity were selected as independent variables, which would influence distribution of droplets deposition. Subsequently, the Box-Behnken experimental design with four factors and three levels was performed, and the mathematical model was established by using Design-Expert software, then the effects of various parameters and their interactions were analyzed as well. The results showed that effects order of four parameters on distribution of droplets deposition were as follows: sprinkler swing speed, sprayer forward velocity, spraying distance, and spraying flow rate. The optimal spraying parameters were spraying flow rate of 185mL/min, spraying distance of 2m, sprayer forward velocity of 8cm/s and sprinkler swing speed of 5(°)/s, then the coefficient of variation of droplets distribution of 1.632% was obtained.