Abstract: The hazards, safety evaluation methods and preventive measures of tailings reservoir were systematically studied. The fault tree analysis (FTA) of a tailings reservoir was performed. The results showed that the ways and causes of the tailings reservoir failure and tailings leakage were various, with 17 and 12 ways, respectively. Close attention should be paid to these ways in the actual production process and great efforts made to investigate them and strengthen the pre-control. According to the different conditions that may appear in tailings reservoir, scientific and reasonable countermeasures should be put forward, and pre-control strengthened, which could greatly reduce the losses caused by tailings reservoir dam failure and tailings reservoir leakage.