The underlying weathered argillaceous siltstone of Nanchang Metro tunnel is eroded by groundwater seepage for a long time, which leads to the migration and loss of fine particles, destroys the rock mass structure and affects the safe operation of the tunnel. In order to study the influence mechanism of groundwater seepage on particle migration, the mass loss test of weathered argillaceous siltstone particle migration under groundwater seepage was carried out, the relationship between the Talbol power exponent n and the mass loss rate, porosity and compaction thickness of the sample was investigated. The results show that the mass loss rate of the samples under different compaction thickness increases first and then decreases with time. The proportion of fine particles in the sample increases, and the variation range of porosity increases, the porosity of each group of samples changes rapidly in the first 10~20 min, and the mass loss is more obvious. The permeability of the sample is affected by both porosity and gradation. The relationship between permeability and porosity is a power exponential function, and the coefficient k_r increases with the increase of n in a good logarithmic function, the coefficient λ_r increases linearly with n, and the correlation coefficients are all greater than 0.99.