The invention discloses an iron-base metal organic framework material with high adsorptive selectivity on C6 isomers, and a preparation method and application thereof. The method comprises the following steps: (1) respectively dissolving 2,2-bis-(4-carboxyphenyl)-hexafluoropropane and iron clusters in DMF; (2) dropwise adding the DMF solution of 2,2-bis-(4-carboxyphenyl)-hexafluoropropane into the DMF solution of iron clusters, dropwise adding glacial acetic acid and carrying out stirring; (3) carrying out filling into a stainless steel high-pressure reaction kettle, and carrying out temperature programmed control hydrothermal synthesis reaction; and (4) carrying out washing, centrifuging and drying to obtain the iron-base metal organic framework material. The iron-base metal organic framework material has high adsorptive selectivity on C6 alkane isomers, and under same conditions, the adsorptive selectivity of the material on normal hexane is more than 3 times higher than the adsorptive selectivity of 5A molecular sieves and other traditional adsorbents, and the material also has good chemical stability and hydrophobicity. The material can separate C6 isomers from straight run gasoline and has good potential application prospects.