In recent years, there has been increasing attention on biomechanical robot arm such as manipulators equipped with bi-articular actuators. Planetary gear system is used to recreate the bi-articular actuators mechanism. In this paper, a Non-Interference control method is proposed for planetary gear system in order to recreate the ideal bi-articular actuators mechanism. By adjusting the gain of the Non-Interference controller the influence between the gears of the planetary gear system is reduced and the performance of the system is increased.