Abstract: In order to consider the fact that the drainage behavior of soil boundary is a continuous process with time in practice, it studied the one-dimensional nonlinear consolidation problem of soil with time-dependent consolidation coefficient considering the time effect of boundary drainage, and the classical nonlinear relationships in terms of the compression and permeability of soils were introduced. The approximate analytical solution for the consolidation problem was obtained by means of variable separation and Laplace transformation, and then the present solution was verified through a degeneration and comparison with existing solutions. Based on the present solution, the influences of the ratio of compression index to permeability index (N_q), the ratio of final effective stress to initial effective stress (C_c/C_k) and interface parameters (α and β) on the consolidation behaviors were discussed in detail. The results show that, under the continuous drainage boundary, the location of the undrained plane in soil is dependent on the interface parameters and varies with time; when C_c/C_k>1, with the increase of N_q, the settlement rate increases in the early consolidation stage, while the opposite is true in the later stage. The value of interface parameter of drainage boundary has great influence on reflecting the drainage rate, so it is necessary to determine the value of interface parameters when calculating the consolidation rate of foundation in engineering.