Abstract: The dewatering velocity of geotextile tubes filled by soil with high clay (silt) particle content is very slow. That cannot meet the requirements of construction speed that a layer of geotextile tubes must be completely filled and preliminary solidified within one day. Several large-scale field model tests are conducted to verify the previously proposed construction methods, which combines actively discharging muddy water with the alternately filling and discharging methods. The indexes including pore water pressure, consolidation degree, water content, particle gradation and dry density of the filled soil in different positions within the geotextile tubes are real-time monitored during the whole filling and discharging process. Through the monitoring data, the comprehensive dewatering velocities of different construction methods are comparatively analyzed. The results have verified the feasibility and actual effect of the proposed dewatering method for high clay (silt) particle-content soil-filled geotextile tubes.