This　study　presents　the　design,　synthesis,　and　comprehensive　characterization　of　a　novel　series　of　D-π-A　type　malononitrile-derived　chromophores,　BTC-1–BTC-4.　Combining　various　spectroscopic　techniques,　nonlinear　Z-scan　measurements,　and　quantum　chemical　calculations,　we　revealed　the　intricate　relationship　between　nonlinear　optical　properties　and　the　interplay　of　molecular　structure,　intramolecular　charge　transfer　(ICT),　and　dipole　moments　(μ).　Our　experimental　and　computational　findings　corroborate　that　the　polarization　degree　in　the　ground　state,　the　charge　separation　in　the　excited　state　and　twisted　intramolecular　charge　transfer　(TICT)　collectively　dictate　the　nonlinear　optical　properties　of　the　compounds.　Notably,　BTC-1　exhibits　an　exceptional　nonlinear　absorption　coefficient　β　value　(2×10−8　m　W−1),　attributed　to　its　optimized　charge　transfer　efficiency　and　pronounced　degree　of　charge　separation.　Our　findings　provide　actionable　insights　for　the　rational　design　of　high-performance　organic　Nonlinear　optics　(NLO)　materials　with　potential　applications　in　advanced　photonic　devices.　©　2024　Wiley-VCH　GmbH.