ABSTRACTIn order to investigate the anti‐friction and anti‐wear performance of different crystal forms nano MoS2 in paraffin oil. Freeze‐drying method combined with hydrothermal was used to prepare different crystal forms nano MoS2 and their microstructures were characterised by X‐ray diffraction (XRD) and scanning electron microscopy (SEM). The anti‐friction and anti‐wear performance of MoS2 nanoparticles as lubricat additives under different working conditions was investigated by the ball‐and‐disk friction and wear testing machine and the mechanism of friction and wear reduction was investigated. The results showed that the thickness of the floral sheet MoS2 flakes was about 10 nm and the particle size of the spherical MoS2 was about 90 nm. When the addition concentration was 3 wt%, the friction coefficient of the floral sheet MoS2 in paraffin oil was lower at 0.094, which was 29.3% lower than that of the pure paraffin oil, the width of the abrasion marks was 24.2% lower than that of the pure paraffin oil and the wear rate was 71.6% lower than that of the pure paraffin oil; The friction coefficient of the spherical MoS2 with 2.5 wt% addition was 0.082, which was 38.3% lower than the friction coefficient of pure paraffin oil, 24.1% lower than that of paraffin oil in terms of wear scar width and 81.9% lower than that of paraffin oil in terms of wear rate.