阐述了一种与地形紧密结合的基于最优控制理论的航路规划方法。该方法利用二维三次卷积插值法构造地形函数， 采用三维的航路规划进行地形跟随、地形回避和威胁回避， 并对俯仰角进行ＰＤ （比例微分） 控制。该方法计算量小， 大大减小了规划时间， 提高了规划结果的实时性， 最优控制理论结合ＰＤ控制使得航路的三维规划鲁棒性好，有效地抑制了振荡和发散， 为低空突防的飞行器提供了很好的参考飞行航路。 This paper elaborates a route planning method based on the optimal control theory which is closely integrated with the terrain. The method uses two-dimensional cubic convolution interpolation method to construct the terrain function, uses three-dimensional route planning to follow the terrain, avoids the terrain and avoids the threat, and performs PD (proportional-derivative) control on the pitch angle. The method has the advantages of small computation, greatly reducing the planning time and improving the real-time performance of the planning results. The optimal control theory combined with PD control makes the three-dimensional navigation route planning robust and effectively restrain oscillation and divergence, Of the aircraft provides a good reference flight route.