Abstract: In design of a radial gate, conventional finite element (FE) simulations often have errors, relative to field measurements, that lower the accuracy in analysis on its dynamic behaviors and vibration reduction control. To address the problem, this paper presents a rapid method for building a dynamic analysis model of a radial gate, using MATLAB-MSC. Patran/Nastran combined simulations with eigen-sensitivity based optimization. The main idea is to extract the lumped mass matrix from the traditional static FE model and to derive the corresponding dynamic FE model under the constraints of geometric and dynamic characteristics of the gate by performing mass redistribution through a combined application call. We adopt a perturbation method to construct a target model for the main frame of the gate, and demonstrate the validity of this method by applying iterative approximation based on an eigen-sensitivity optimization approach. Furthermore, a comparison with the existing parametric optimization methods shows that our method can generate more accurate FE models of dynamic analysis while guaranteeing minimum variation. Using this approach, a FE dynamic model is constructed for a full hydroelastic radial gate according to its measured data, and calculations show that accurate modeling can be achieved with fewer iterative steps.