Fabricating dense film of the oxadiazole-based photoelectron materials is usually limited by its low crystallization, which will influence charge injection in the devices. In this paper, multiwalled carbon nanotubes (MWCNTs) are functionalized by 2-(4-aminophenyl)-5-naphthyl-1,3,4-oxadiazole (APND) to form the MWCNTs-APND conjugate. The formation of MWCNTs-APND dense films may be attributed to attraction between coplanar APND, flexible and linear MWCNTs, and π-stacking between APND and MWCNTs. The APND and MWCNTs-APND were characterized by Fourier transform infrared spectrum, proton nuclear magnetic resonance spectrum, scanning electron microscopy, X-ray diffraction, ultraviolet-visible (UV-Vis) absorption spectrum, and photoluminescence spectrum, and nonlinear electrical measurements. The results indicate UV-Vis absorption of MWCNTs-APND in N, N-dimethylformamide solution is broadened and red-shifted. Its photoluminescence spectrum shows a narrower band than that of APND. The MWCNTs-APND dense films have the same perfect nonlinear electrical properties as those of MWCNTs ones, which is suitable for the potential applications of optoelectronic devices.