The floating reference frame formulation is widely used for analysis of flexible multibody dynamics in the industry because the various model order reduction (MOR) techniques can be applied. The MOR techniques represent a deformation field through eigenvalue analysis, and then a set of the selected eigenvector is used for the reduced system. In this process, it is very important to select the boundary conditions and dominant modes of a flexible body. That is usually dependent upon the engineer’s experience. In this paper, we proposed a method for selecting deformation field for flexible multibody analysis using dynamic correction modes. To verify the usefulness of the proposed method, the numerical simulation of a double pendulums is carried out.