Abstract: The problem of spacecraft attitude control is investigated in this paper. To solve this problem, a finitetime sliding mode control strategy is proposed based on a finitetime timevarying sliding manifold in the present of uncertainty and external disturbance．The stabilization is proved and the parameter selection method is given. By using the proposed control strategy, the closedloop system is asymptotically stable and the convergence time is finite. In addition, the attitude tracking error can converge in a given time. Consequently the dynamic response of the closedloop system is determined by the sliding mode dynamics. Numerical simulations are finally provided to illustrate the performance of the control strategy.