Abstract: This paper presents a case study of the Xinjiang Santanghu mining area planning EIA, describes the ecological water requirement calculation methods and procedures in the mining area planning environmental impact assessment (EIA).The results showed that the downstream of the water transfer project must ensure the ecological water requirement of 4.85 million m3/a, if we ignore the ecological water requirement calculations, which will lead to a larger deviation in the water resources bearing capacity analysis of the mining area planning environmental impact assessment (EIA), and further lead to a larger deviation of evaluation conclusions. The case study can be used for reference to the ecological water requirement calculation in the other mining area planning environmental impact assessment (EIA).