Abstract: The antenna pedestal, as the transmission mechanism to support the antenna array, is a typical part of mechanic scanning radar. The dynamic characteristics of the antenna pedestal determine the pointing accuracy of the antenna beam. In this paper, with the 1st Lagrange function as the modeling theory, the flexible multi-body dynamics model of the antenna pedestal is built based on ADAMS software. The dynamic characteristics of the antenna pedestal are analyzed including the contact force, the angular velocity and the angular acceleration of the internal gear pair and compared with the simulation results of the rigid multi-body dynamics model. The simulation results are in agreement with the experimental results, which shows that the flexible multi-body dynamics modeling method is feasible and reasonable. This simulation method can provide excellent reference for structure design of the similar transmission mechanism.