TECHNOLOGY FOCUS - POLYMERS - Preparation (Claimed): The preparation of (I) comprises:(i) reacting 1,7-Dibromo-3,4:9,10-perylene tetracarboxylic dianhydride and 3, 4, 5-trialkoxyaniline to obtain a perylene tetracarboxylic acid imidodicarbonic diamide dibromo monomer; (ii) reacting 3', 4'-diamino-2, 2':5', 2''-terthienyl compound and diphenylglyoxal compound to obtain 2,3-Diphenyl-5,7-di(thiophen-2-yl)thieno(3,4-b)pyrazine compound; (iii) the obtained compound with N-bromosuccinimide to obtain another monomer of the thieno (3, 4-b) pyrazine compound; and (iv) under the oxygen-free condition, carrying out the polymerization reaction for the perylene tetracarboxylic acid imidodicarbonic diamide dibromo monomer and the thieno (3, 4-b) pyrazine compound prepared with the fluorene diborate in the organic solvent to obtain (I). Preferred Composition: The mole ratio of the 1,7-Dibromo-3,4:9,10-perylene tetracarboxylic dianhydride to the 3, 4, 5-trialkyl (oxygen)-1-aminobenzene is 1:(3-10). The reaction time is 1-72hours, reaction temperature is 60-100 degrees C, and solvent is quinoline, iminazole, butanol, N-methyl-2-pyrrolidone or propionic acid. The mole ratio of the 3', 4'-diamino-2, 2':5', 2''-terthienyl compound to the diphenylglyoxal compound is 1:(1-1.5). The reaction time is 1-72 hours, reaction temperature is 20-78 degrees C, and solvent is ethanol, ethyl acetate, methanol or water. The mole ratio of the 2,3-Diphenyl-5,7-di(thiophen-2-yl)thieno(3,4-b)pyrazine compound to the N-bromosuccinimide is 1:(2-2.5). The reaction time in the trichloromethane, N, N-dimethylformamide or tetrahydrofuran solvent is 1-72 hours. The mole ratio of the tetracarboxylic acid imidodicarbonic diamide dibromide to the thieno-(3, 4-b) pyrazine compound to the fluorene diborate is x:y:1, reaction temperature is 50-120 degrees C, and reaction time is 24-72 hours. The organic solvent is tetrahydrofuran, glycol dimethyl ether, benzene, N, N-dimethylformamide or toluene. The catalyst is the organic palladium catalyst or the mixture of the organic palladium catalyst and the organic phosphine ligand. The organic palladium catalyst is tetrakis(triphenylphosphine)palladium(0)or palladium(II) acetate. The mole ratio of the organic palladium catalyst and the organic phosphine ligand of the mixture is 1:(2-20). Preferred Method: The polymerization in (iv) comprises addition of catalysts, in which the adding amount is 0.01-5% by mole ratio of the total material. The reactions from (i)-(iv) are carried out under the oxygen-free condition. The oxygen-free condition is inert gas condition.