In the light of the structural characteristics of a shaped nozzle, the optimized data model is established by using the total divisor experiment in design of experiment (DOE). Through the simulation calculation and regular analysis, the multiobjective optimization method is used to optimize the structure parameters of the shaped nozzle so that their maximum stress, maximum deformation and mass are all appropriate. Three main structure parameters of the shaped nozzlethe height of the stiffening ring, the thickness of the stiffening ring and the thickness of the nozzle wall, are selected. After analyzing their respective influence rules on the mass, maximum stress and maximum deformation, and getting the transfer function, the optimal solution factor combination is obtained by using the response optimizer. The result shows that the mass of the shaped nozzle is reduced by 24.45% in the case of ensuring the use of strength requirements.