The invention relates to an insoluble and refractory metal modified hyperbranched polymer and a preparation method thereof. The insoluble and refractory metal modified hyperbranched polymer is prepared by dropwise adding an acetic acid metal salt solution into a carboxyl-terminated hyperbranched polymer solution, the metal modified hyperbranched polymer is a network polymer formed by crosslinkinga carboxyl-terminated hyperbranched polymer with metal ions, has insoluble and refractory properties, is insoluble in most of organic solvents at the temperature of lower than 80 DEG C and is refractory in a range from the room temperature to the temperature T, wherein T is larger than or equal to 370 DEG C, and crosslinking is realized in ways that acid radical ions at terminals of molecules of the carboxyl-terminated hyperbranched polymer are connected with the metal ions by ionic bonds while oxygen atoms on double bonds inside the molecules of the carboxyl-terminated hyperbranched polymer are connected with the metal ions by coordinate bonds. By using the method disclosed by the invention, the problem that it is difficult to process and mold a blend when the hyperbranched polymer is blended is solved, the prepared metal modified hyperbranched polymer has the insoluble and refractory properties under a general processing condition.