Aimmin at adjusting weighting matrices in the design of the linear quadratic Gaussian/loop transfer recovery(LQG/LTR) flight control law for a small-scale unmanned helicopter,an optimal tuning method based on the artificial bee colony(ABC) algorithm is proposed．By using the LQG/LTR robust control method, the designe of a two-loops hierarchical control scheme for automatic flight control of the helicopter is completed. In order to optimize the feedback controller, the global search capability of the ABC algorithm is adapted to minimize the performance index. A series of flight simulation in consideration of the disturbance of wind turbulence and system noise are conducted to investigate the effectiveness and the control performance of the proposed scheme. The simulation results show the feasibility and superiority of the proposed ABC algorithm in respect to improving the robustness and performance of the controller.