In this paper, a new dynamic model for the flexible hub-beam system is proposed by using the principle of continuum medium mechanics and the finite element discretization method. In the proposed model, the coupling deformation of any element of the beam is only related with the nodal coordinates of this element. So this model is suitable to the rotating beam in an arbitrary shape. Numerical examples of slender beams in straight and irregular shapes are carried out to demonstrate the validation of the proposed model. Simulation results indicate that the proposed model can be used valid for dynamic description of flexible rotating beam in irregular shape, and for both low and high rotation speeds.