In order to improve the design efficiency of pressure hull structure of underwater vehicle, the optimal design method of pressure hull structure based on parametric analysis and response surface approximation model was studied. Five dimensions of the pressure hull structure of a certain type of underwater vehicle were determined as design variables, and the thin shell theory and CCS specification were used in preliminary design to confirm feasible region. Opt LHD method was used to determine test sample points within the feasible region space, and the sample point of ABAQUS parameterized driving was studied, and second order polynomial response surface model under ultimate load was established. Taking the limit load and the shell quality as the optimization target, the multi objective optimization of pressure hull was carried out by using NSGA-II to obtain Pareto optimal set. Results show that the ultimate load of optimization design increases 41.68% comparing with that of preliminary design, while shell quality reduces 27.26%. Parameterized method can simplify optimization process and improve optimization efficiency which provides a reference for underwater vehicle structure optimization.