Rotors of Micro Air Vehicle (MAV) and Small Unmanned Aerial Vehicle (SUAV) are facing deterioration of aerodynamic characteristics at low Reynolds numbers (Re). In order to ameliorate the problem, an aerodynamic design method of the rotors for MAV and SUAV is established in this work. The aerodynamic designs of three efficient small-scale rotors are completed successively using a thin circular-arc cambered airfoil with 6% camber and 5% thickness. The computational fluid dynamics (CFD) method is used to compare and analyze the aerodynamic performance of the three rotors in the hovering state, and the experimental verification is also completed. The deviation between the computational results and the experimental data is small, indicating that the computational results is highly accurate. The computational results show that the rotor hovering thrust and Figure of Merit (FM) are significantly enhanced after optimization. The hovering thrust and FM of the optimized rotor are increased by 17.6% and 0.053 respectively compared with the baseline rotor when the rotation speed is 3000rpm, which proves the effectiveness of the aerodynamic design method of the rotors for MAV and SUAV established.