A method for recovering high-purity magnesium sulfate includes: a pre-precipitation step of mixing an alkali precipitant and seawater; a concentration step of reacting a precipitate formed in the pre-precipitation step with sulfuric acid, followed by filtering to obtain a first eluate; a first precipitation step of adding ethanol to the first eluate, and then removing a first precipitated solid to obtain a second eluate; and a second precipitation step of precipitating magnesium sulfate solid by further adding ethanol to the second eluate from which the first precipitated solid has been removed.