The unloading type sheet pile has enormous complexity of load transfer method and coordination mechanism, thus exploring the structure of the bearing capacity performance is of great significance, especially the bearing capacity characteristics are studied by combining with specific engineering cases for the field measurement. The results show that the walls in the 16 m at the amount of horizontal displacement over time are gradually increased and stabilized, and the overall maximum horizontal displacement of the anchor wall occurs at the anchor point. Drawbar pull is substantially increased in the early deep dredging period, and tends to be steady in the later period. The distribution of lateral earth pressure is approximately determined by the distribution of earth pressure at rest, and the fluctuation is due to uneven distribution of various soil and interlayer, but the overall trend remains unchanged. The excess pore water pressure is reduced at the height of -20 m or more in the active region, following a slight increase under the height of -20 m in the passive zone. All results show that the unloading sheet pile has high bearing capacity mechanism and working performance functions, and can be widely used in large-scale complex deepwater pier projects.