In order to improve the operation ability of unmanned aerial vehicles (UAV), this paper designs a lightweight manipulator for quadrotor UAV. First, according to the requirements of the task and the load of the UAV, an aerial manipulator with lightweight and small moment of inertia is designed, and the 3D model of the manipulator is established in the Creo software. The maximum deformation and stress under different load conditions were analyzed by Ansys Workbench software, and the dynamic analysis was carried out in ADAMS software to obtain the driving moment required by each joint of the manipulator under load conditions. Finally, the dynamic model of the aerial manipulator system is established according to the Newton-Euler method, and the maximum workspace of the manipulator in the hovering state is generated by the Monte Carlo method. The research results show that the deformation and stress level are small, and the workspace meets the operation requirements, which proves that the designed manipulator has certain engineering application value.