In this article, we present a novel aerial robot with a suspended saw (ARSS) for pruning trees that are close to electric power lines. The Robot’s movement process includes free flight and aerial pruning. We first established a dynamic model and designed a controller based on the Active Disturbance Rejection Control (ADRC) on the model. Aiming at the problem of saw swing and residual oscillation during the free flight movement, we adopt the linear state feedback to design a swing angle controller. Finally, we use Matlab/Simulink and CoppeliaSim for simulation, and the simulation results verify the effectiveness and feasibility of the controller.