This study developed a muscle biomechanics analysis system that combines the shoulder and elbow joints. Using the limb activity data obtained from the motion analysis system, the kinematic data of the limb in space, such as velocity, acceleration, and the force and torque borne by the joint, are obtained. Combined with the motion of the musculoskeletal simulation system, the muscle direction and rotational lever arm are calculated. In addition, by combining the physiological parameters of the muscle and using numerical calculation methods, the force generated by the contraction of the muscle in dynamics is obtained.