Abstract: Selecting the mining area with frequent surface landslide in the process of in-situ leaching, the infiltration rate of rare earth from two ore blocks in filed was tested based on four common models fitting the water infiltration characteristic. The results show that the whole infiltration process can be divided into three phases: the infiltration rate of 0~45 min is the rapid change stage, the infiltration rate of 45~125 min is slowly change phase and after 125 min the infiltration rate gradually achieves the stability. The fitting effect of Kostiakov is better than the other three models with the average ore initial infiltration rate being 0.113 cm/min, the steady infiltration rate of 0.063 cm/min in the first sample region, the average ore initial infiltration rate of 0.162 cm/min and the steady infiltration rate of 0.101 cm/min in second sample region. The infiltration rate increases with the rise of sand and gravel content and decreases with the rise of clay content. At the same time, the infiltration rate is in the negative correlation with the ore moisture content. Hydraulic conductivity in vertical direction shows a rapid decreasing trend with the increase of depth. When liquid injection intensity is too excessive and far more than the hydraulic conductivity, surface seam liquid can not infiltrate in time, which will lead to the decrease of slope safety factor and the occurrence of surface landslide.