采用球型模型和点位－点位模型对超临界二氧化碳的自扩散系数及苯或萘在超临界二氧化碳中的无限稀释扩散系数进行了分子动力学模拟．结果表明，球型模型及点位－点位模型均可较准确地预测二氧化碳的自扩散系数，球型模型因形式简单，准确度相对较差；点位－点位模型准确度虽高，但需较长的模拟机时．两种位能模型所获得的准确度相当，但点位－点位模型可以更精细地反映体系的微观结构． The spherical model and point - point model were used to simulate the self - diffusion coefficient of supercritical carbon dioxide and the infinite dilution diffusion coefficient of benzene or naphthalene in supercritical carbon dioxide. The results show that the spherical model and the point-point model can predict the self-diffusion coefficient of carbon dioxide more accurately. The spherical model is relatively simple in form and accuracy is relatively poor. However, the accuracy of the model of point-point model is high, Need longer simulator time. The accuracy obtained by the two potential energy models is comparable, but the site-point model can more finely reflect the microstructure of the system.