TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The catalyst is tris(dibenzylidene acetone)dipalladium, tetrakis(triphenylphosphine)palladium or bis(triphenylphosphine)palladium dichloride. The mole ratio of organic palladium catalyst and (II) is 1:2000-1:5.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Method: The Stille coupling reaction is carried out at 50-120 degrees C for 6-100 hours. The separating and purifying steps comprise adding toluene and deionized water into the stille coupling reaction mixture, extracting organic phase with ethanol to obtain precipitate, filtering the precipitate to obtain filter solid, drying the filter solid, dissolving the dried mixture in chloroform, then again precipitating with methanol, purifying the filter solid by neutral alumina chromatography, then extracting with acetone, collecting acetone solution and then precipitating and filtering. (II) is prepared by adding 2-bromo-5-(5-bromo-2-thienyl)thiophene compound of formula (IV) into n-butyl lithium, tetrahydrofuran and tributyltin chloride under the protective of gas atmosphere at -78 degrees C, stirring the reaction mixture for 1 hour, where the mole ratio of (IV) and n-butyl lithium is 1:2, and the mole ratio of (IV) and tributyltin chloride is 1:2, raising the temperature to room temperature for 6 hours, carrying out termination reaction with saturated sodium chloride aqueous solution, extracting reaction liquid with ethanol, drying the organic phase, filtering to obtain filter liquid, and removing the solvent in the filter liquid. (III) is prepared by providing 4-bromo-7-(7-bromo-5-iodo-4,5-dihydro-2,1,3-benzoselenadiazol-4-yl)-6-iodo-6,7-dihydro-2,1,3-benzoselenadiazole (V) and but-2-yne compound of formula (R1-CC-R2) (VI) in a mole ratio of 1:2 under the protective gas atmosphere, carrying out ring closure reaction in the presence of an organic alkali and a catalyst containing an organic solvent and then purifying and separating, where the organic alkali is tributylamine, and the catalyst is acetic acid palladium. The separating and purifying steps of (III) comprises carrying out ring closure reaction of the mixture with water, extracting the ring closure reaction mixture with dichloromethane, retaining organic layer, then drying with an anhydrous sodium sulfate, filtering and distilling to remove solvent, and separating by a silicon glue chromatographic column.