Abstract: Considering inflecting effect, this paper presents a flexible cable model, which can be used for analyzing the dynamic behavior of the electrodynamic tether (EDT) deorbiting system. The model can describe tether inflecting and bowing under action of electrodynamic drag and gravity gradient induced force, and the influences on electro motive force and electrodynamic drag. Two mathematical simulations are employed to show the differences between the flexible cable model and the drumbell model. Vibration of the EDT system during deorbiting course is discussed. The simulation result shows that vertical response is the main vibration of EDT.