Abstract: It is so important to do research on the computer simulation of Purex used in nuclear fuel reprocessing system based on the datum relating to Purex since the simulated program can be used in analyzing the influence of input parameter on Purex and optimizing the input parameter of Purex. In other countries, such studies carried out earlier, a semi-theoretical model named Richardson model was formed as the representative of the distribution model. Based on the stirred tank model and the dispersion model respectively, so many simulation program were developed to simulating the extraction behavior of the mixer-settler contractor and the pulsed column. Because computer simulation of Purex was carried out later in China, there are only some researches on the distribution model and the simulation of the mixer-settler contractor, a large gap is still existed.