在使用分子动力学方法对微正则系综进行模拟的情况下，以单原子粒子系统为例，给出了标度因子在国际单位制下的数学表达式.然后说明了如何把物理量重新标度得到无量纲公式，使得在模拟中计算更加方便.给出了无量纲化操作中时间单位的物理意义.最后，推导了趋衡过程的速度标度因子在教材中常用的数学表达式.

In the case of using the molecular dynamics method to simulate the micro-canonical ensemble, taking the monoatomic particle system as an example, the mathematical expression of the scaling factor under the International System of Units is given. Then it explains how to rescale the physical quantity to obtain the dimensionless formula, which makes the calculation more convenient in the simulation. The physical meaning of the time unit in the dimensionless operation is given. Finally, the mathematical expressions commonly used in textbooks for the speed scaling factor of the balance process are derived.