In order to improve the spraying performance of the air nozzle, the atomization flow field between air nozzle and spray surface was numerically simulated by using computation fluid dynamics (CFD), and the structure parameter and operating parameters of the nozzle were optimized globally combined with the response surface methodology. Firstly, a hotwire anemometer measuring system was set up to verify the accuracy of the numerical calculation model. Then, a threefactor central composite experiment was designed to establish the response surface regression model and mathematical optimization model with the inclination angle α of shaping air holes, the pressure p1 of annular air hole, the pressure p2 of shaping air holes as design variables and the center pressure pc of spray surface as target variable. Furthermore, the structural parameter and operating parameters of the nozzle were optimized, and the optimal combination of nozzle characteristic parameters was obtained. The results show that the optimization design of the characteristic parameters of air nozzle by response surface methodology can effectively improve the atomization flow field in the nozzle, the central pressure of the spraying surface after optimization is reduced by 57.6%, which is conducive to produce uniform coatings. By analyzing the response surface graph, the interaction law of each characteristic parameter on the spray performance can be summarized.