With the development of biomedicine and microcontroller technology, above knee prosthesis has been improved rapidly. However most current researches just focus on the single knee joint, and ignore the coupling between knee joint and ankle joint, which do not meet the needs of patients who need to perform multi-joint coordinated movement. This paper presents a new control method using bipedal robotics technology, bio-inspiration based on CPG net. According to this method, primary controller embedded in knee\ankle joint can receive the command from subject, recognize the movement mode, and send the start command to lower which realize the movement of above knee prosthesis. The previous findings show that sEMG can be employed to identify the movement mode based on SVM. And nonlinear oscillator, used for controlling multi-legged robot, can be employed to realize the lower limb movement. Further this paper explores the biodynamic effect of multi-joint, and tries to find the coupling rule and identify the MIMO neuromuscular model.