According to a high aspect ratio and V-shaped empennage UAV, a flight control strategy in low altitude and low speed with large disturbance was researched. The UAV's motion state was simulated and analyzed. Using six-degree-freedom nonlinear equations, an adaptive PID controller was designed. By applying the designed algorithm to the experiment of fixed-attitude, fixed-high and flight-path tracking, the adaptive controller effectively inhibited the influence of large disturbance on the UAV's attitude and position. The simulation and experimental results show that the controller meets the requirement of the flight missions and the dynamic performance is well realized.