The influence mechanism of fine grain content on static liquefaction characteristics of soil is complex and deeply affected by soil properties. In view of the large number of iron tailings reservoirs in the Panzhihua area in the upper reaches of the Yangtze River, an in-depth understanding of their static liquefaction characteristics is essential to ensure the safety of tailings reservoirs. Therefore, in order to explore the influence of different fine grain contents on the static liquefaction characteristics of iron tailings in Panzhihua area, the iron tailings with fine grain contents of 0, 20％, 40％, 60％ and 100％ were studied by consolidated undrained triaxial test. The influence of fine grain content on the stress-strain behavior, static liquefaction potential and critical state line of iron tailings were analyzed. The test results show that the fine grain content has a significant effect on the static liquefaction characteristics of iron tailings. The anti-liquefaction ability of iron tailings increases first, then decreases, and then increases with the increase of fine grain content. There are two thresholds in this process, and the threshold decreases with the increase of confining pressure. According to the critical state line, Panzhihua iron tailings are most easily liquefied when the fine grain content is 60％. This study can provide a reference for further understanding the static liquefaction characteristics of iron tailings reservoirs in Panzhihua area.