质点动能定理由牛顿定律及质点运动推导而来,功能原理是通过质点系动能定理及保守力功的基础上延伸而来,而机械能守恒定律则是质点系的功能原理的推广。本文分析了应用质点系功能原理求解物理问题的一般步骤,还对两个具体实例分别运用牛顿定律、质点动能定理、功能原理进行计算,从而体现应用质点系功能原理解决物理问题更加简单、方便的优越性。 The theorem of particle kinetic energy is deduced from Newton’s law and particle motion. The principle of function extends from the kinetic energy theorem of particle system and the power of conservatism, while the law of conservation of mechanical energy is the promotion of the functional principle of particle system. In this paper, we analyze the general steps to solve the physical problems by using the functional principle of particle system, and also calculate the kinematic theorem and the functional principle of two specific examples by using Newton’s law, particle kinetic energy theorem and functional principle respectively, which shows that the application of the functional principle of particle system is more simple and convenient Superiority.