目前，计算天体公转轨道及公转速度的过程涉及到许多高级数学概念和物理原理，对于青少年理解难度较大.为方便对天体运动的深入理解，本文利用更易理解的圆锥曲线及其性质展开对天体运动轨道方程及公转速度的讨论与计算，得出简洁的公转速度公式，且相较于非纯理论的计算方法，不仅对计算过程的描述更为精确，而且归纳了所有速度区间下的运动情况，体现了数学在物理学中的重要性，希望能激发青少年对于物理学的热爱．

At present, the process of calculating the orbits and orbital velocities of celestial bodies involves many advanced mathematical concepts and physical principles, which are rather difficult for teenagers to understand. To facilitate a deeper understanding of celestial motion, this article uses conic sections and their properties, which are easier to understand, to discuss and calculate the orbital equations and orbital velocities of celestial bodies. A concise formula for orbital velocity is derived. Moreover, compared with non-purely theoretical calculation methods, it not only provides a more precise description of the calculation process but also summarizes the motion situations under all velocity ranges, demonstrating the importance of mathematics in physics. It is hoped that this will inspire teenagers' love for physics.