The invention relates to a polyester amphipathic hyper-dispersant and a preparation method thereof to satisfy the demand of dispersion of solid particles in different polar media. The technical characteristics are as follows: first, ester monomer copolymerizes under initiator action to prepare a polyester chain segment of random structure, then the polyester chain segment and one of methacrylic acid and acrylic acid copolymerize to prepare carboxyl terminated polyester compound, at last, the carboxyl terminated polyester compound and amine graft react, the obtained solvent chain is polyester,and the anchoring radical is amino or amino and alcohol radical. The invention has the advantages that: 1) the synthesis and preparation of the hyper-dispersant is simple, the production period is short and the cost is low. 2) The hyper-dispersant has good amphipathic structure. Inorganic powder that is modified by the hyper-dispersant shows good amphipathic performance can satisfy the demand of dispersion of the powder in different polar media, thus popularizing the application range of the modified powder and reducing the material processing cost.