TECHNOLOGY FOCUS - POLYMERS - Preparation (claimed): The organic polymer (I) is prepared by mixing cyclopentadiene derivative of formula (i), thiophene derivative of formula (ii) and catalyst in a molar ratio of 1:1:0.005-0.05 under anaerobic conditions, adding sodium carbonate aqueous solution, adding toluene as solvent, refluxing at 60-100 degrees C for 24-72 hours, separating, and purifying. The amount of sodium carbonate aqueous solution is 5-10 times of amount of cyclopentadiene derivative (i). Preferred Process: The purification of organic polymer (I) is carried out by adding toluene to the reaction system, adding deionized water, extracting organic phase, removing at least portion of the solvent in the organic phase by vacuum distillation, dropwise adding resultant organic phase to anhydrous methanol, precipitating, filtering, drying, obtaining solid powder, dissolving the solid powder in chloroform, removing catalyst using neutral aluminum oxide chromatographic column, removing chloroform, and obtaining purified organic polymer (I). The cyclopentadiene (i) is prepared by dissolving bromine-containing compound of formula (iii) in tetrahydrofuran solvent under anaerobic conditions, stirring at -70 degrees C to -85 degrees C, slowly adding n-butyl lithium, stirring for 0.5-4 hours, reacting at -70 degrees C to -85 degrees C, slowly injecting 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane, heating to room temperature for 10-48 hours, separating, and purifying. The purification of cyclopentadiene (i) is carried out by adding saturated sodium chloride solution to the separated product, extracting by chloroform, drying the organic phase using anhydrous sodium sulfate or anhydrous magnesium sulfate, collecting the filtrate, removing the solvent, obtaining crude product, subjecting crude product to silica gel column chromatography by using dichloromethane as eluent, and separating. The bromine-containing compound (iii) is prepared by adding 9-(bis(methylsulfanyl)methylidene)-2,7-dibromo-9H-fluorene to tetrahydrofuran solvent under protection of nitrogen, continuously stirring, then adding diethyl ether solution of bromine compound of formula: R1MgBr (iv), reacting at 0 degrees C for 30 minutes or more, adding dilithium tetrachlorocuprate of tetrahydrofuran solution, stirring for 4-8 hours, carrying out neutralization reaction using sodium hydroxide solution for 10-20 minutes, separating, and purifying. The purification of bromine-containing compound (iii) is carried out by collecting the reaction product by filtration using diatomite, extracting organic phase using ethyl acetate, adding organic phase to sodium hydroxide aqueous solution with concentration of 10%, sodium pyrosulfite solution and saturated salt solution, performing decompression distillation using sodium sulfate, subjecting silicon gel column chromatography using petroleum ether, and performing recrystallization process using 2-methyl pentane as solvent. The 9-(bis(methylsulfanyl)methylidene)-2,7-dibromo-9H-fluorene is prepared by mixing anhydrous dimethyl sulfoxide solution of 2,7-dibromofluorene and potassium tert-butoxide in a molar ratio of 1:2-2.4 under nitrogen protection, then adding carbon disulfide, stirring for 10-20 minutes, adding methyl iodide, continuously stirring, separating, and purifying. The purification of 9-(bis(methylsulfanyl)methylidene)-2,7-dibromo-9H-fluorene is carried out by adding the reaction product into an ice water, adding concentrated aqueous ammonia to remove unreacted methyl iodide, filtering, washing the filter residue by water, and drying using mixed solvent of ethyl acetate and tetrahydrofuran in a volume ratio of 2:1. Preferred Properties: The molar ratio of bromine-containing compound (iii) with n-butyl lithium is 1:2-4. The molar ratio of n-butyl lithium and 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane is 1:2. The molar ratio of 9-(bis(methylsulfanyl)methylidene)-2,7-dibromo-9H-fluorene and bromine compound (iv) is 1:2-2.4. The molar ratio of bromine-containing compound and dilithium tetrachlorocuprate is 25-50:1. The molar ratio of 2,7-dibromofluorene and carbon disulfide is 1:1-l.2. The molar ratio of 2,7-dibromofluorene and methyl iodide is 1:1-1:1.2.