Abstract: This is an article in the field of mineral processing engineering. In this article, the effect of main ions in seawater on graphite flotation is explored by flotation test of graphite pure minerals. The results show that five main metal ions in seawater can promote graphite flotation to a certain extent, with the action intensity of Ca²⁺ > Mg²⁺ > Na⁺ > K⁺ > Sr²⁺. Only F^- and SO₄^2- anions have an influence on graphite flotation, in which SO₄^2- has a strong inhibiting effect, and F^- is relatively weak, which almost can be negligible.