本文的中子阴级由聚乙烯、导电基底（Ａｌ）和碘化铯二次电子发射体组成．文中建立了一个此中子阴级的新的物理模型，并采用ＭｏｎｔｅＣａｒｌｏ方法模拟了中子同阴极作用产生低能二次电子的物理过程．模拟得到的出射二次电子能谱和产额与实验结果和理论分析符合得较好．我们还得到了最大探测效率时各中子阴极组分的最佳厚度 In this paper, the neutron cathode is composed of polyethylene, conductive base (Al) and cesium iodide secondary electron emitters. In this paper, a new physical model of this neutron-cathode is established, and the Monte Carlo simulation is used to simulate the physical processes of neutron-cathode interaction to generate low-energy secondary electrons. The simulated emergent secondary electron spectra and yield are in good agreement with the experimental and theoretical analysis. We also get the best detection efficiency for each neutron cathode component of the best thickness