Abstract: Fine-grained tailings have the characteristics of low permeability coefficient，slow consoli‐ dation speed and poor mechanical properties. The construction of high dams is not conducive to the stabili‐ ty of tailings reservoirs. In addition，the influence of complex terrain directly affects the safe operation of fine-grained tailings dams when special conditions such as failure of drainage facilities or increased rain‐ fall occur. Taking a 200 m high tailings dam as an example，the tailings dam in three valleys at the same time，the three-dimensional numerical analysis method is used to carry out the analysis of the interaction law of seepage field and stability and the study of control saturation line. The results show that due to the comprehensive influence of complex topographic conditions such as excessive gully angle，regional seep‐ age and narrow dam axis，the spatial seepage characteristics of high dam are obviously different. The satu‐ ration line in the dam abutment area is 2~3 m higher than that in the surrounding area，which is the most critical area for dam seepage control. When the dam height is 200 m，the depth of the control saturation line is 23 m. The key area of the dam body adopts local horizontal drainage measures to encrypt and control the local infiltration line to ensure the safe operation of the tailings reservoir.

Key words: high dam tailings reservoir, fine-grained tailings, seepage field, stability analysis