CR39可以用于激光等离子物理实验中的离子探测，并给出离子数目、种类和能量信息。通过采用唯象模型，利用离子在CR39中径迹形成的阻止本领动力学方程以及粒子群智能算法对径迹形成的过程进行了数值化模拟，研究了CR39中离子径迹在刻蚀过程中的演化过程，获得了入射离子能量和径迹直径、深度的对应关系，并且发现当离子射程与刻蚀深度相等时，径迹深度最大，给出了利用总刻蚀时间计算最大径迹深度对应的临界能量的公式。

CR39 detector can be used to detect the ions in laser-plasma physics experiments and to obtain information about the number, kind and energy of incident ions. Using phenomenological model, we numerically simulated the formation process of ion track in CR39 using energy loss dynamics equation and particle swarm optimization (PSO) algorithm thus studied the revolution of the ion track in CR39 during the etching process. The corresponding relationship between ion energy and track diameter and depth was obtained. It is found that when the ion range was equal to the etching depth in CR39, the track depth was the largest. The equation of the critical energy with which the track is the deepest and determined by the etching time was given.