The invention relates to a hexaiodobenzene compound and a contrast medium containing the same, and further provides a method for preparing the compound. Specifically, compared with the conventional clinic non-ionic contrast medium dimer (such as iodixanol and iotrolan), the osmotic pressures of the compound and the conventional clinic non-ionic contrast medium dimer are similar, but the compound has smaller viscosity, wherein, groups which are represented by R1, R2 and R3 are listed in the specification.