The structure of a Hydraulic Damped rubber Mount (HDM) with a column channel and decoupling membranes is analyzed. Using direct Fluid-structure Interaction (FSI) Finite Element Analysis (FEA) method, the integral finite element model is developed, and the calculation of the dynamic characteristics and the analysis of the working process under different excitation frequencies are carried out. The results show that the decoupling membranes deform in the low frequency range, and the notch peak value and the peak value of the dynamic stiffness and the peak value of the loss angle are changed with the variation of the number and the stiffness of the decoupling membranes. On the basis of the original design, disturbing plates with different structural parameters are added respectively and the dynamic characteristics of these HDMs are recalculated. The influence of the disturbing plate on the peak values and their corresponding frequencies of the dynamic stiffness and the loss angles is analyzed, and the laws of the dynamic characteristic curves changing with the diameter and rod length of the disturbing plates in the low frequency range are also studied. The effectiveness of the finite element analysis and calculation is verified by the experiment. The FEA modeling method based on the direct FSI technology is well in reflecting the real working process of the interior structures in the HDM and the change rule of the dynamic characteristics, which can be used in the performance analysis and design process of HDMs with complex structures.