The change of mud drainage and consolidation plays an important role in reasonable arrangement of drainage system in the construction process of hydraulic fill dam. By taking moderate silty loam as the research object, mud was separately packed at three soil-water ratios(1:1, 1.5:1 and 2:1) in four polyethylene corrugated pipes of 50, 100, 150 and 200 cm in height and indexes for quantity of water discharge, up-water separating, penetration and the amount of consolidation-subsidence were measured. Results show that all the indexes increased with increasing mud height at the same soil-water ratio. However, the indexes decreased with increasing soil-water ratio in the same height mud. The amount of discharged water and subsidence were mainly observed in the first 24 h, with the maximum 89.48% and 93.24% in total quantity, respectively. Therefore, in practice, it is necessary to enhance the previous up-water discharge at low soil-water ratio and meanwhile, no arrangement of drainage systems in surface mud is needed except enhancing the drainage measures of penetrating water.