Abstract: The technique of finite element analysis in the design of tank is applied.The finite element analysis model of tank has been set up and the configura tion of some type tank has been optimi zed.The stress and the quantum of dis placement in different pressure were obtained by using the nonlinear analysis of the material.It offers useful date for design of tank shell.As a result of the configuration optimization,the weight of tank was reduced and the availability of lo ad in launch can be improved.