在低空突防作战中，防空系统对重要位置提供完全封闭的保护，进攻飞机需要穿越防空体系，如何提高飞机在威胁区的生存概率是当前研究的重点。在考虑地形遮蔽的基础上，建立雷达探测模型；综合考虑飞机在威胁区运动过程中RCS(Radar Cross Section)的变化，得到雷达探测概率指标;结合飞机在威胁区突防时间指标，构建了突防方向函数模型，并根据任务选择不同的突防方向。为配合飞机更好地执行作战任务，通过对雷达实施压制干扰，有效减小了雷达威胁等级。仿真结果表明，选择特定的突防方向，能提高飞机的生存概率；配合支援干扰，能使飞机避开雷达威胁，提高飞行器低空突防能力。

In low altitude penetration combatair defense system provides completely closed protection to important position，and how to increase the survivability of fighter plane when crossing the threatening area is the keypoint in current research.We established a radar detection model based on radar terrain masking blind space.Considering the change of Radar Cross Section(RCS) of the aircraft during its movement in the threatening areawe obtained the radar detection probability.On which basis and the penetration time indexthe penetrating direction function was established，and penetrating direction was determined according to the different missions.To enhance the survivability of airplaneblanket jamming was implemented to decrease the threatening of radar.The result of the software simulation demonstrates that selecting a specified penetrating direction and using blanket jamming will enable airplane to avoid radar threatening detection and improve the survivability of it.