四维速度矢量在狭义相对论中具有承前启后的作用，一方面关联着光速不变原理决定的相对论四维时空，另一方面关联着相对性原理决定的协变力学定律和电动力学定律.长期的教学实践表明，重视和加强四维速度矢量及其承前启后作用的教学，可以更有效启发初学者理解狭义相对论的来龙去脉和理论体系，更有利于促进他们夯实物理基础.

The 4-velocity as a crucial node is linked to two aspects in the special relativity. One aspect is the relative 4-space-time due to the postulate of the constancy of the light speed, while the other aspect is the covariant mechanics and electrodynamics laws due to the postulate of the relativity. Teaching practice for a long time tells us that an emphasis and enhancement in the teaching in the 4-velocity and its connection role can inspire learners to understand the ins and outs of the whole theoretical system, and facilitate them to lay a solid foundation of physics.