TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The catalyst is tris(dibenzylideneacetone)dipalladium, bis(triphenylphosphine)palladium dichloride or tetrakis(triphenylphosphine)palladium. The molar amount of the catalyst is 0.5-20% the molar amount of (II).    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preparation (Claimed): The preparation of (I) comprises dissolving bromo-substituted silolo-bis(benzothiadiazole) compounds of formula (II) and thieno(3,4-b)thiophene-4,6-diylbis(tributylstannane) compounds of formula (III) at molar ratio of 1:1.5-1.5:1 in an organic solvent under an inert gas atmosphere, then adding a catalyst, and performing Stille coupling reaction for 6-100 hours at 50-120 degrees C, and separating and purifying to obtain (I). Preferred Method: (II) is prepared by: (i) reacting 4-nitrobenzene-1,2-diamine with thionyl chloride and pyridine for 24 hours at 80-90 degrees C, and separating to obtain 5-nitro-2,1,3-benzothiadiazole (IIa), where the molar volume ratio of 4-nitrobenzene-1,2-diamine to thionyl chloride is 1.5:1 mol/l, and the volume ratio of thionyl chloride to pyridine is 50:1; (ii) brominating (IIa) with hydrobromic acid and liquid bromine for 4 hours at 127 degrees C to obtain 4,7-dibromo-5-nitro-2,1,3-benzothiadiazole (IIb), where the mass fraction of hydrobromic acid is 40%, the molar volume ratio of (IIa) to hydrobromic acid is 4:1 mol/l, and the molar volume ratio of (IIa) to liquid bromine is 5.3:1 mol/l; (iii) subjecting (IIb) to coupling reaction under presence of copper powder catalyst for 3 hours at 120 degrees C to obtain 4,4' dibromo-6,6'-dinitro-linked-2,1,3-benzothiadiazole (IIc), where the molar ratio of (IIb) to copper powder is 0.2:1; (iv) reducing nitro group of (IIc) to amine group using tin dichloride at 100 degrees C for 10 hours, and followed by carrying out diazotization reaction with sodium nitrite in presence of hydrochloric acid for 30 minutes at below 5 degrees C, and then reacting with potassium iodide for 12 hours to obtain 4,4'-dibromo-6,6'-diiodo-linked-2,1,3-benzothiadiazole (IId), where the molar ratio of (IIc) to tin dichloride is 1:10, the molar ratio of (IIc) to hydrochloric acid is 0.92:1, the molar ratio of (IIc) to sodium nitrite is 0.53:1, and the molar ratio of (IIc) to potassium iodide is 0.054:1; and (v) reacting (IId) with n-butyl lithium in a dimethylformamide solvent under anaerobic conditions at -90 degrees C for 2 hours, and then reacting with substituted silyl dichloride compounds of formula (R1R2-Si(Cl)2) (IV) at room temperature for 10 hours to obtain (II), where the molar ratio of n-butyl lithium to (IId) is x, and the molar ratio of (IV) to (IId) is 2:1. (III) is prepared by adding 4,6-dibromothieno(2,3-c)thiophene compounds of formula (V) to tetrahydrofuran under inert gas atmosphere, cooling to -78 degrees C, then adding n-butyl lithium at -78 degrees C, stirring and reacting for 1-2 hours, adding tributyltin chloride, then performing reaction for 1 hour at -78 degrees C, then warming to room temperature and reacting for 6 hours and separating to obtain (III), where the molar ratio of (V) to n-butyl lithium is 1:2, and the molar ratio of (V) to tributyltin chloride is 1:2. The separation purification comprises adding de-ionized water and toluene into the reaction liquid and performing extraction, distilling the collected organic phase under reduced pressure, adding an anhydrous ethanol, separating out precipitate, filtering, drying obtained solid powder, dissolving the solid powder in chloroform, separating by silica gel column chromatography and eluting with toluene as eluent, distilling the chromatographic liquid under reduced pressure, sedimentation of methanol, filtering, extracting obtained solid using acetone for three days in a Soxhlet extractor, again sedimentation of methanol, filtering, and vacuum filtering of the liquid at overnight to obtain (I). Preferred Components: The organic solvent is tetrahydrofuran, ethylene glycol dimethyl ether, benzene or toluene.x = less than or equal to 2 to less than 4.