In order to analyze the underground seepage flow pattern of uranium tailings reservoir and the seepage stability of the dam body under heavy rainfall,this paper takes a uranium tailings reservoir in southern China as the research object,and based on the actual operation of the tailings dam,establishes the physical model of the dam according to the similarity principle,and GEO-studio finite element analysis software is used to verify and predict the results.The results show that the each displacement monitoring point is in a decreasing trend under the precipitation pressure of the two rainfalls; the rising height of the saturation line is not obvious,and the water level of each monitoring point increases first and then decreases.At the water level monitoring points 1,4,and 5 osmotic damage has occurred inside the dam.No osmotic damage occurred at the water level monitoring points 2 and 3.The four displacement gauges showed large lateral displacement and  settlement.That is to say the stability of uranium tailings dam cannot meet the requirement under two heavy rainfall conditions;the numerical simulation saturation line is slightly lower than the physical model experiment,numerical simulation value of displacement is close to the experimental value of physical model,indicating that the simulation effect is good and that the finite element model can be used to simulate the underground seepage flow pattern and stability of uranium tailings dam under heavy rainfall.