Preparation method of reprocessable thermosetting biodegradable polyester based on transesterification

The invention discloses a preparation method of reprocessable thermosetting biodegradable polyester based on transesterification. The reprocessable thermosetting biodegradable polyester is prepared from biodegradable polyester, polyol, an epoxy monomer and a stabilizer by using a reaction type twin-screw extruder on the premise of abandoning a metal catalyst. The biodegradable polyester prepared by the preparation method disclosed by the invention has ester groups and hydroxyl groups which are formed by reacting hydroxyl groups on an intermediate product with epoxy groups of epoxy monomers at the same time; ester groups and hydroxyl groups can participate in ester exchange reaction in reprocessing after forming to form a covalent cross-linked network, so that the performance is improved; under a certain condition, under the condition that the crosslinking density is not changed, a topological network is changed through an ester exchange reaction, so that thermoplasticity is brought; meanwhile, the method keep