Design/methodology/approach The best modifier for MoS2 was selected by theoretically calculating the electron distribution in the molecular orbitals of six modifiers in different solvents and the Fukui indices of the modifiers. Fourier infrared spectroscopy and UV-visible absorptiometry were employed to precisely determine whether MoS2 was successfully modified. At the same time, four-ball friction wear, scanning electron microscopy and 3D profilometer morphology were utilized to meticulously analyze the effect of different contents of modifiers on the tribological effect of MoS2 modification. Findings The results showed that the surface modification of MoS2 has the best tribological performance at a triethanolamine (TEA) content addition of 48 ml. Originality/value In this study, the authors simulated the effects of different modifiers on the modification of molybdenum disulfide. The advantages of the TEA modifier were validated by analyzing the orbital and molecular adsorption energies. To further investigate the effect of TEA content on its frictional properties, the structure, modification, wavelength and absorbance of MoS2 powder were characterized. Subsequently, the tribological properties of TEA-modified MoS2 solutions were analyzed by friction and wear experiments, and the optimal content of the modifier TEA was revealed. This study provides a theoretical foundation for the optimal modification conditions of TEA in nanofluids. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-01-2025-0016/