According to the actual production situation of the mine, the step-by-step pile discharge sedimentation column was carried out, and the physical parameters of the different depth after the tailings slurry deposition was obtained , so as that the deposition characteristics of the step-by-step pile discharge slurry was obtained. Besides, the gray correlation analysis method was used to analyze the influence of the parameters. The results show that the interface height of mud water is closely related to the mud content when the mud deposition of bauxite tailings is stable, but it is not to do with the mud concentration. It is speculated that the mud water separation ratio of 30% of the mine discharge concentration is 1:1.018; there is "water locking" phenomenon between the layers of each pile discharge, and the physical parameters such as water content, density, void ratio, permeability coefficient, compression coefficient and volume compression coefficient are along the depth direction It has the characteristics of stage by stage and each level is independent of each other; there is a complex relationship between the physical parameters, among which the water content has a significant impact on other physical parameters. The correlation degree of water content on density, void ratio, permeability coefficient and compression coefficient is 0.945, 0.952, 0.856 and 0.889 in order.