The finite element method is widely used to describe the elastic deformations of flexible bodies, which leads to a large number of elastic coordinates and large computational burden. In order to reduce the degree of freedom of flexible bodies, a modal method and a Krylov method were used to reduce the degree of freedom of the flexible hub beam system. Then the finite element model, and the reduced models based on modal method and Krylov method were used to do simulation respectively. The numerical simulations show that using the Krylov method shows faster convergence than using the modal method. It means that Krylov method is an efficient method to implement model reduction of flexible multibody system.