Biodegradable branched aromatic polyester-aliphatic polyester multi-block polymer

The invention relates to a biodegradable branched aromatic polyester-aliphatic polyester multi-block polymer and a preparation method thereof. By combining excellent biological degradability of aliphatic polyester, excellent mechanical property, thermal performance and stability of aromatic polyester and improved physical and mechanical performances of branched aliphatic polyester, the invention provides the biodegradable branched aromatic polyester-aliphatic polyester multi-block polymer. The multi-block polymer is a branched multi-block copolymer comprising an chain segment I and a chain segment II, or a branched multi-block polymer comprising the chain segment I and a chain segment III, or a branched multi-block polymer comprising the chain segment I, the chain segment II and a chain segment III. According to the multi-block polymer, the defects of the aliphatic polyester in performance are overcome; and the multi-block polymer has the advantages of high viscosity of fused mass, high strength of the fused