While highly desired in integrated optical circuits, multiresponsive and tunable nonlinear optical (NLO) active 1D (sub) wavelength scale superstructures from organic materials are rarely reported due to the strong tendency of organic molecules to self-assembly in centrosymmetric modes. Here a solution-processed assembly approach is reported to generate non-centrosymmetric single-crystalline organic microfibers with a cumulative dipole moment for anisotropic combined second-and third-order NLO.