An integrated attitude-orbit controller based on extended state observer (ESO) is designed for spacecraft to settle down the unavailability of angular velocity and centroid velocity during on-orbit flight.First,the spacecraft's integrated attitude-orbit kinematics and dynamics model is presented based on dual quaternion.Second,an extended state observer is designed for the case of velocity screw information missing,which takes the model parameter error and external disturbance into account,and the finite time convergence of the observation error is analyzed by using Lyapunov stability theorem.Then a fast terminal sliding mode controller for integrated attitude-orbit control is designed based on the above extended state observer,and its finite time convergence is analyzed.Finally,a numerical simulation is given to verify the effectiveness of the control system.