Abstract: Six cyano-substituted sp²-carbon fully conjugated molecular materials (namely cn0−cn5) were rapidly synthesized via sonochemical approach based on the Knoevenagel condensation. Combined with thin layer chromatography (TLC) and nuclear magnetic resonance spectroscopy (¹H NMR), the concentration optimization of reactants and selection of alkali catalysts were performed. When the concentration of aldehyde group was 1 mol/L and NaOH was utilized as catalyst, six fluorescent molecules were efficiently synthesized in 5−23 min, and their corresponding yields were all higher than 97%. The optical properties of these as-obtained materials were characterized by UV-vis spectroscopy and fluorescence spectroscopy. The application of organic light-emitting diodes of cn2, cn3 and cn4 was preliminarily explored. Under the excitation of blue-violet light, blue-green, light purple and bright green luminescence were found respectively.