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Aiming at the problem of weak wind power performance of straight gas-assisted nozzle, the effects of nozzle tail parameters on the flow wind power performance of new “tail first contraction and then expansion” pneumatic nozzle were studied with the combination of single point wind speed test and numerical simulation. The three dimensional numerical model was established for the pneumatic nozzle based on the Reynolds averaged N-S equation and realizable turbulence model, and the correctness and validity of computational fluid dynamics (CFD) model were also verified by the wind speed test. Secondly, the wind performance of two types of nozzles was compared by numerical calculation. The results showed that outlet average wind speed was 1.36 times of the straight nozzle when the total inlet pressure was 105600Pa and the static pressure was 105200Pa. In order to study the effect of the tail parameters (the retract length of the convergent section and the height of the expansion section) on the wind performance of new type nozzle, the agent mathematical models were established by the optimal Latin hypercube design and radial basis function neural network (RBFNN), thus greatly facilitating the automatic modeling and compensating for the large amount of calculation for CFD. The R2 variance of outlet flow and outlet average wind speed were 0.98354 and 0.98728, respectively, the agent mathematical model could be used for performance prediction and guiding the scientific configuration of structure parameters. The intelligent decision and optimization research of the influence factors were researched based on agent mathematical model. With the increase of the height of expansion and increase of retract length, the average wind speed at the outlet end showed a downward trend, while the flow rate showed a trend of first increase and then decrease. The air flow reached the maximum value of 0.0179kg/s when the height of the expansion section was 1.08mm and the retract length of contraction in convergent section was 5.39mm; the average wind speed reached the maximum value of 67.9m/s when the height of the expansion section was 0mm and the retract length of contraction in convergent section was 0mm. Multi-objective optimization was made, the optimal Pareto set solution of the wind performance parameters were obtained, which provided a diversified reference for optimization match design of pneumatic nozzle and orchard.