Abstract: The difficulty of SOTM antenna is to suppress the disturbance of antenna pointing accuracy caused by carrier movement. Compensation for disturbance can significantly improve the dynamic performance of antenna. The traditional control method realizes the measurement of the disturbance angular velocity with a rate gyro, and it’s difficult to accurately obtain the disturbance on the antenna rotation axis. In this way, limited improvement effect occurs, as only a certain proportion is compensated into the speed loop input. Therefore, this paper proposes a disturbance compensation method based on a state observer. A disturbance model is obtained by collecting the angular velocity of the inertial navigation system when the antenna is working normally on a typical road surface, and approximating the disturbance spectrum by using a shaped filter. A disturbance observer model is designed to estimate the angular velocity of the disturbance, and the test is carried out on the vehicle-mounted mobile antenna. The test results show that, compared with the traditional disturbance feedforward compensation, the proposed method reduces the angular error peak by 13% and RMS by 43%, which can better adapt to the tracking road conditions.