Abstract: The seepage of muddy water has significant influences on the anti-filtration design in hydraulic engineering, muddy water irrigation and seepage control in embankments. At present, the theoretical approaches are predominantly stable seepage methods, neglecting the coupled effects between coarse and fine particles during seepage process. In this study, a seepage apparatus is fabricated to investigate the infiltration characteristics of particles in coarse-grained soil columns under various combinations of factors, including muddy water with different compositions, coarse-grained soil columns with non-uniform coefficient, and hydraulic heads. A differential equation for calculating the seepage with variable permeability coefficients in muddy water is derived. Through comparative validation and formula modification, it is revealed that the particle deposition rate in coarse-grained soil and the content of particles with the control size C_0.075 follow a Boltzmann function relationship. C_0.075 is a significant influencing factor, dictating the migration, deposition and clogging morphology of particles in the coarse-grained soil columns. Four predominant morphologies are identified: surface accumulation clogging (S type), surface-internal dual clogging (S-I type), internal pore clogging (I type), and transient pore clogging (P type). As the value of C_u of the coarse-grained soil columns increases and the porosity decreases, the migration of particles in the coarse-grained soil becomes more difficult, and the filling characteristics of the coarse-grained soil columns are poor. The hydraulic head intensifies the migration velocity of particles in the coarse-grained soil columns but also accelerates their deposition and clogging at the top. During the S type phase, the rate of decrease in the permeability coefficient from 0 to 2 cm in depth is the highest, resulting in the overall minimum permeability coefficient during clogging, with a gradual reduction in the relative porosity under the depth below 2 cm. For the S-I and I type columns, the permeability coefficient in the lower part lags significantly behind that in the upper part, with the critical depth of the relative porosity (approximately 4~6 cm). The overall relative porosity is basically unchanged for the P type columns.