The structure of the metal sealing ring of the underwater clamp connector has a great influence on the sealing performance.In order to obtain the optimal seal ring structure size,the relationship between the contact stress of the metal seal ring and the structural parameters was analyzed through the finite element statics analysis and optimization module.Using flange cone inclination,sealing ring arc radius,half width and edge thickness as design variables,the maximum contact stress and minimum flange axial force as the objective functions,and the maximum equivalent stress of the sealing ring as the constraint variable,the multi-objective optimization model of underwater clamp connector was established.The model was optimized with response surface method,and the optimal size combination of sealing ring under multi-objective optimization was obtained.The results show that among the four parameters of flange cone inclination,sealing ring arc radius,half width and edge thickness of sealing ring,the flange cone inclination has the greatest influence on the axial force required by the sealing ring.The smaller the angle,the smaller the axial force required by the sealing ring.Under the same contact stress,the maximum equivalent stress of the optimized seal ring is reduced by 7.7% and the axial force of the flange is reduced by 37.3%.It is concluded that under the same sealing pressure,the axial force required by the optimized sealing ring is smaller,so the service life of the sealing ring is prolonged.