Abstract: The mining water-proof performance of Neogene red soil is a critical factor for the safe extraction of super large mining height fully mechanized faces and the protection of shallow ground water. The results of multiple research methods, such as exploration of the occurrence structure of red soil layer, the test of engineering geological characteristics, the in-situ permeability test, the detection of mining water insulation and the full-cycle monitoring of mining response in the working face with super large mining height, The occurrence law, lithology structure and natural state water insulating effect of red soil in 122104 working face of Caojiatan Mine were studied. The mining stress appearance and deformation development process in red soil layer during fully mechanized mining with super large mining height were measured. The evolution law of water insulating performance of red soil layer during mining process was explored, and the mining response characteristics of red soil layer were revealed. The results show that: ① The red soil strength decreases when there are calcareous nodules, and the permeability tends to increase due to disturbances. The mineral composition of the red soil layer contains a high proportion of clay minerals, which exhibit expansion and deformation characteristics when exposed to water. ② The segmented water injection experiment shows that the red soil layer has maintained a stable water-resisting area of more than 30 m during the advancement of the working face. The long-term dynamic monitoring results of the aquifer water level of the Salawusu Formation show that the borehole water level slowly decreases and gradually remains stable. The mining has no directly affect the Quaternary loose aquifer, and the red soil layer effectively isolates the Quaternary groundwater from flowing downward; the results of borehole peeping show that the lower part of the red soil layer is stable, the integrity is good, the primary cracks are not developed, and the water insulation is good. ③ The mining response monitoring system of the impermeable layer is established, and the real-time online monitoring of the whole space deformation and settlement of red soil layer in the whole process of mining is realized. The monitoring results show that in the process of working face advancing, the displacement curve presents hysteresis and nonlinear characteristics, and the red soil layer appears discontinuous deformation. During the mining process, the result shows that the mud cover effect appears in the red soil layer, the post-mining strain recovery cracks are closing, and the water insulation capacity is enhanced. ④ The ratio of soil-rock thickness 122104 working face is 1∶2, and the red soil layer shows the characteristics of zonal mining response in the horizontal and vertical directions during the advancing process of working face. Horizontally, it can be divided into " mining weak response area", "mining strong response area" and "post-mining closure area". Vertically, it can be divided into "upper unstable water-proof zone", "middle stable water-proof zone" and "lower mining failure zone". The red soil layer extends the mining response time of the soil horizontally, and maintains a stable water-proof area in the deep part of the red soil layer vertically. The characteristics of the response lag and the stable water-proof layer are the critical factor to ensure the stable water-proof performance of the red soil layer.