Abstract: For a kind of adaptive output regulation control that can only obtain the reduced dimension output information of the system, in this paper, a model reference adaptive control method for output regulation based on Kalman filter was proposed, which used the nonlinear estimation ability of Kalman filter to realize the estimation of output measurement information to full dimensional state information, and used the observation state to realize adaptive tracking of the output of closed-loop system to the reference state to ensure the stability of each closed-loop signal. The above method was applied to the control of the drag-free stable platform in the space gravitational wave detection mission, and the stable output tracking ability of the drag-free control system was realized with unknown parameters and additional disturbances. Based on the theoretical analysis of each closed-loop signal stability realized by the Lyapunov method, numerical simulation comparison verifies the effectiveness of the method over the tracking ability of the general output tracking adaptive control method.