Abstract: The inverted pendulum is a typical high order system with multi-variable, non-linear, strong-coupling, fleet and absolutely instable properties. It is a typical ideal model to prove new control theory and techniques. During the control process, pendulum can effectively reflect many key problems such as equanimity,robust,follow-up and track. This paper studies the LQR control method of the straight line double inverted pendulum. First,the mathematical model of the double inverted pendulum is established,a LQR controller is designed and then the system simulation is conducted. Finally,two versions of the VC and Simulink control program based on the technology of Windows dynamic link library calls and multimedia timer technology are designed. The system successfully achieves steady sway control.