高铁护栏的保护原理是利用土基、立柱、横梁的变形来吸收碰撞能量，并迫使失控车辆改变方向，回复到正常的行驶方向，防止车辆冲出路外，以保护车辆和乘客，减少事故造成的损失。车辆对其碰撞时，由于护栏有良好的耐撞性能和吸收能量的作用，既不容易被撞毁。
The protection principle of high-speed rail guardrail is to use the deformation of soil foundation, column and beam to absorb collision energy, and force out of control vehicles to change direction and return to normal driving direction, so as to prevent vehicles from rushing out of the road, so as to protect vehicles and passengers and reduce the loss caused by accidents. When the vehicle collides with it, the guardrail is not easy to be damaged due to its good crashworthiness and energy absorption.