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��