本文对常用的测定水相中扩散系数的方法——膜池法进行了改进,并用改进的膜池法对先锋Ⅱ在水中的扩散系数进行了测定。实验结果表明,用金属膜替代玻璃膜,这种改进的膜池法所用实验时间只是传统方法的三十分之一,所得到的扩散系数是可信的。 In this paper, the commonly used method to determine the diffusion coefficient in the aqueous phase - the membrane pool method was improved, and the improved membrane pool Pioneer Ⅱ in the water diffusion coefficient was measured. The experimental results show that, with the metal film instead of the glass film, the improved membrane cell method used experimental time is only one-thirtieth of the traditional method, the resulting diffusion coefficient is credible.