As an important equipment for satellite signal reception and transmission, the satellite antenna needs to be rotated in real time to achieve real-time tracking of the target and complete signal transmission during applications. Antenna driving mechanism is generally composed of motor and other components, which will cause some structural vibration during rotation. For high-stability satellite applications, the vibration disturbance torque is a major factor affecting the satellite stability. In order to study characteristics of the disturbance torque, the disturbance data from the antenna under different rotation conditions should be measured. In this paper, the frequency characteristics of disturbance torque of a rotating satellite antenna using stepper motor as driving motor is tested and discussed.