Abstract: Center symmetry plane three connecting rod is studied. This model can be used to describe the movement of satellite with symmetry solar pane in outer space with weak gravitation. Since the system is nonintegrable, in general, the movement of such system is complicated. The Lagrange motion equation of the system is established, and synchronous movement is studied.Exact solution of synchronous movement is presented and movement disciplinarian is studied. It proved that under certain condition, it exist periodic motion. Results will be helpful to analysis the complicity of near synchronous movement of the system.