The transport process of neutral beam ions in HT-7 Tokamak was simulated by Monte-Carlo method. The neutral-plasma collision processes taken into account, which include the charge-exchange, electron impact ionization, ion impact ionization, etc. 应用MonteCarlo方法,模拟了Tokamak装置中的中性粒子的输运过程,模型考虑了中性粒子在等离子体中的电荷交换、电子碰撞电离、离子碰撞电离等离化过程。