Combining with the indoor clogging tests of loose foundation in Tibet,the permeability clogging process of loose foundation was simulated based on particle flow method.Under the constant head of 2.2 m,numerical micro-simulation was made in three cases,which was not adding any clogging materials,or adding the clogging materials with the diameter between 0.075-0.500 mm and 0.5-1 mm.The dynamic changes of fluid velocity,permeability coefficient,porosity and loss amount were recorded in the numerical simulation.The results have shown that fluid velocity and permeability coefficient decreased rapidly,when adding the clogging materials with the diameter between 0.5 mm and 1.0 mm.With seepage stability,fluid velocity value was very low.By using computer simulation in the two cases,we got that both cases induced clogging effect.Clogging effect was due to one of the interval of particles rather than one size,which could be seen in the phenomenon of the second case.To some extent,numerical method is useful in the study of clogging problems,which gave the same result obtained in laboratory test and simulation test.These data provided basis and reference for further study of clogging problems,and also provided a new method to study the micro-scale permeability clogging mechanism.