Recently, researchers show great interest in Unmanned Aerial Vehicle(UAV) path planning problem due to development of artificial intelligence algorithms. However, the convergence of these kinds of heuristic methods can not be proved. Therefore, the UAV path planning problem has been modeled as a linear optimal control problem to ensure the convergence. But the computing time will increase exponentially as the scale of the problem enlarge. Hence, the Receding Horizon Control(RHC) is introduced to the problem to guarantee the efficiency. Nevertheless, how to choose a proper receding horizon span to keep balance between efficiency and accuracy becomes a new problem. An adaptive strategy is proposed to choose a proper parameter to meet the real-time requirement and fuel consuming in this paper. The strategy has better performance in the two simulation scenes, which indicates the effectiveness of the algorithm.