Abstract: For the slip of the soft soil foundation in the storage yard of a wharf, the root pile-net composite foundation is used for reinforcement. The geotechnical centrifugal model tests are carried out to study the effects of pile length on settlement characteristics of the root pile-net composite foundation under super-large loads. The foundation, root piles, reinforced cushion, dust net foundation, track beam foundation and ore loads are simulated in the tests. The settlement variation laws of composite foundation with different pile lengths are analyzed the under super-large loads. The surface settlement of the composite foundation is distributed in a pan shape. The settlement decreases with the increase of the pile length, and the distribution shape becomes sharp. The settlement of the equal-length pile scheme is far greater than that of the design length pile scheme, and the distribution shape is sharper. The settlement of the pile-net composite foundation with the design pile length meets the use requirements of controlling within 80 cm under the loads of 350 kPa in two years. The test results show that the arrangement scheme of root piles is reasonable and feasible.