The recent development of unmanned aerial vehicle flight control creates a strong demand for higher control accuracy and control quality. In this paper, the precise control and stable hovering problem are studied for unmanned helicopters. To solve the problem, we propose a hovering controller for dual-loop of unmanned helicopters. Firstly, the nonlinear mathematical model of unmanned helicopters is established based on Newton-Euler’s laws. Then, we respectively design the position model and attitude model. In the position model, we use the cascade PD controller to realize the precise control; In the attitude model, we use the cascade PD controller to realize the stable hovering. Simulation results show the effectiveness of the conclusions made in this paper.