Abstract: In this paper, a numerical model on fluid-structure interaction is established and the validation of the model is carried out. The doubly asymptotic approximation for external domain is used to model the external fluid, the doubly asymptotic approximation for internal domain is used to model the internal fluid and the nonlinear finite element software ABAQUS is employed to model the structure. Based on the numerical model, the influence of internal fluid to the dynamic response of double ring-stiffened cylindrical shell is investigated. The main results are as follows. Compared with the analytic solution, the oscillation period and amplitude of late time response obtained by the first order doubly asymptotic approximation decrease. But, the solution of the second order doubly asymptotic approximation agrees well with the analytic solution. The existence of internal fluid makes the plastic deformation and velocity response of double ring-stiffened cylindrical shell decrease.