Stabilization platforms are used widely in different engineering fields such as cameras,telescopes and weapons systems.The requirements are different due to the different applications.But a common requirement in inertially stabilized Line-of-Sight control systems is to point or scan at a target from a moving vehicle.One of the main factors that affect the performance of stabilized Line-of-Sight(LOS)control system is disturbance torque.Firstly,the transfer function between disturbance torque and angular velocity of LOS is given by establishing the system dynamics model.