Abstract: Objective: This study aimed to analyze the muscle co-contraction and pre-activation during brush-knee twist-step and normal walk among long-term Tai Chi practitioners to explore the neuromuscular control strategies of Tai Chi. Methods: Vicon motion capture system, Kistler force plate, and Noraxon surface electromyography system were synchronously used to collect the electromyography (EMG) sign of the rectus femoris, biceps femoris, tibialis anterior muscle, lateral head of gastrocnemius and body posture information while performing the brush-knee twist-step and normal walk. The pre-activation and co-contraction of the knee and ankle joints were calculated by integrated EMG of the rectus femoris and biceps femoris, tibial anterior and lateral gastrocnemius muscles. Results: Compared with normal walk, the average time of the four phases of the brush-knee twist-step was significantly increased; there was a significant difference in the percentage of time in the four phases; the knee joint co-contraction level and pre-activation level decreased, and the ankle joint co-contraction level and pre-activation level increased. Conclusion: Long-term Tai Chi exercises may increase the activation level of the muscles around the knee joint and enhance the synergy between the muscle groups to help stabilize the joint;For the ankle joint, we speculate that the elderly may need greater ankle stability and stiffness. These findings emphasize the influence of neuromuscular control strategies in determining performance and supporting the musculoskeletal system to optimize function and regulate injury risk, and provide references for rehabilitation assessment and training of neuromuscular control disorders.