NOVELTY - A polyethylene glycol dendritic polymer comprises organic diamine as trigger core, polyethylene glycol and acrylic ester as branched repeating unit, and double bond or primary amine group as surface functional group.    USE - Polyethylene glycol dendritic polymer.    ADVANTAGE - The polyethylene glycol dendritic polymer is prepared easily and economically by an environmentally-friendly process.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for manufacture of polyethylene glycol dendritic polymer, which involves preparing branching unit using enzymatic catalyst reaction. A portion of polyethylene glycol is dissolved in organic solvent to prepare 0.5-2 mmol/mL of solution. 2-10 Portions of acrylic ester are added to the obtained solution and stirred uniformly, and Novozyme 435 (RTM: lipase acrylic resin) based on mass-volume ratio of 5-20 mg/mL under stirred conditions of 40-90 degrees C for 36-60 hours. The resulting solution is filtered to remove enzyme, and filtrate is distilled under low pressure, and remaining liquid is separated by column chromatography using petroleum ether or ethyl acetate as eluent, to obtain polyethylene glycol-bis-acrylic ester. The first generation of polyethylene glycol dendritic polymer G1 is prepared by Michael addition reaction in which a portion of organic diamine is dissolved in organic solvent to prepare 0.1-2 mmol/mL of solution and add 0-2 portions of catalyst. 8-30 portions of polyethylene glycol-bis-acrylic ester dissolved in organic solvent, to prepare 0.1-2 mmol/mL of solution. The organic diamine is slowly added dropwise to the polyethylene glycol-bis-acrylic ester solution. The resulting solution is stirred for reaction at 20-60 degrees C for 24-48 hours. The reaction solution is evaporated under low pressure, and remaining liquid is separated by column chromatography using methanol or ethyl acetate as eluent, to obtain polyethylene glycol dendritic polymer G1. The polyethylene glycol dendritic polymer G1.5 is prepared by Michael addition reaction in which a portion of obtained G1 is dissolved in organic solvent to prepare 0.1-2 mmol/mL of solution and 0-2 portions of catalyst are added. 20-60 Portions of organic diamine are dissolved in organic solvent, to prepare 0.1-2 mmol/mL of solution. The obtained G1 solution is slowly added dropwise to the organic diamine solution. The resulting solution is stirred for reaction at 20-60 degrees C for 24-48 hours. The reaction solution is distilled under low pressure, and remaining liquid is separated by Sephadex (RTM: column), to obtain polyethylene glycol dendritic polymer G1.5. The second generation of polyethylene glycol dendritic polymer G2 is prepared by Michael addition reaction in which a portion of obtained G1.5 is dissolved in organic solvent to prepare 0.1-2 mmol/mL of solution and 0-2 portions of catalyst are added. 5-120 Portions of polyethylene glycol-bis-acrylic ester is dissolved in organic solvent, to prepare 0.1-2 mmol/mL of solution. The G1.5 solution is slowly added dropwise to the polyethylene glycol-bis-acrylic ester solution. The resulting solution is stirred at 20-60 degrees C for 24-48 hours. The reaction solution is distilled under low pressure, and remaining liquid is separated by Sephadex (RTM: column), to obtain polyethylene glycol dendritic polymer G2. The processes for manufacture of G1.5 and G2 are repeated, to obtain different algebraic polyethylene glycol dendritic polymer product.