In order to meet the requirements of autonomous docking and combined flight of unmanned aerial vehicles （UAVs）， the aerodynamic configuration of six-ducted UAV was designed. The aerodynamic characteristics of the UAV in hover condition were studied by numerical simulation， the aerodynamic performance changes of the whole machine under different propeller speeds were studied， and the aerodynamic optimization of the propeller was carried out under the duct condition. The results show that the propeller is the main source of hover lift， and with the change of rotation speed， the lift force of the duct always accounts for about 17% of the total lift force. The resistance comes from the upper surface of the vehicle and the motor support， which reaches 10% of the total lift of the UAV. With the increase of the propeller plate load， the power load of UAV decreases. The presence of the duct affects the slip flow characteristics of the propeller， resulting in the increase of the axial speed of the propeller disc， the decrease of the angle of attack of the section airfoil， and the decrease of the working efficiency. By adjusting the distribution of the torsion angle， the propeller efficiency is improved， the lift is increased by 3.3%， and the efficiency is increased by 2.9%.