TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Component: In step (2), the inorganic base is anhydrous potassium carbonate or anhydrous sodium carbonate.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preparation (claimed): Preparing diketopyrrolopyrrole derivative involves: (1) under the protection of inert gas, dissolving 2-cyano-thiophene in tert-butoxide alcohol solvent under heating and stirring, adding dropwise in an alcohol solution of dimethyl succinate and then reacting, post-treatment after completion of the reaction to obtain the compound (II); (2) under the protection of inert gas, the compound (II) with an inorganic base is dissolved in N,N-dimethylformamide, heating under stirring, adding octyl bromide, post-treatment after completion of the reaction to give compound (III); (3) in an inert gas protection and dark conditions, performing bromination reaction for compound (III) with N-bromosuccinimide after completion of the post-processing to give compound (IV); (4) in an inert gas, performing Stille coupling reaction for compound (IV) under palladium catalyst with a 2-(tributyltin)-hexylthiophene refluxed in toluene to give compound (V); (5) in an inert gas under dark conditions, performing N-bromosuccinimide bromination of compound (V) under chloroform, after completion of the reaction, post-treating to obtain compound (VI); and (6) under the protection of inert gas, performing tin coupling reaction the compound (VI) in the presence of a palladium catalyst, with a metal reagent or a boronic acid ester, the reaction is complete, post-treating to obtain pyrrole-dione derivatives; where the metal tin reagent or borate ester compound comprises formulae (VII-1), (VII-2), or (VII-3).Post-processing involves Using a mixed solvent of chloroform and ethanol and recrystallizing the mixed solvent of chloroform and ethanol in a volume ratio of 1:0.4-0.6. In the toluene-water two-phase system in the reaction, the inorganic base is also added. Preferred Composition: In step (3), the molar ratio of N-bromosuccinimide and compound (III) is 1-1.1:1. In step (4), the palladium catalyst is tetrakis (triphenylphosphine)-palladium at 1-10 mol.%. Preferred Components: The alcohol solvent is t-amyl alcohol. The reagent is compound (VI1-1), compound (VI1-2) or compound (VI1-3), the coupling reaction is in toluene or toluene-water two-phase system reaction.