isophthalic disulfonyl chloride or terephthalol and p-phenyldiethynylbenzene can be used as cross-linking agents to further cross-link to form insoluble and insoluble polymers. Under stirring, drop an appropriate amount of isophthalmic chloride into the molten mixed terphenyl, react at 300-310 ℃, and slowly introduce nitrogen to take away the generated HCl and SO2 gases to obtain polyphenylene soluble in chloroform, benzene and other general organic solvents. If excessive amount of isophthalmic chloride is added dropwise, it will further react to generate insoluble polyphenylene.