Considering that the atmospheric kinetic interceptor with invariable rolling rate has quick response and strong coupling, this paper firstly analyzes the advantage and disadvantage of the classic design method of the control system, and then it proposes the gain scheduling method based on the regional pole placement, which finds a Lyapunov function in the whole parameter space to guarantee system stability. Compared with the classic method, the new method is not only stable theoretically, but also convenient in calculation. Simulation results show that controller based on the method which be proposed in this paper has good performance.