In order to improve the tribological properties of low viscosity PAO15 lubricants,spherical and flowershaped MoS2 particles were prepared by hydrothermal method,and the prepared MoS2 particles were characterized by Xray diffractometer (XRD) and scanning electron microscope (SEM).Spherical and flowershaped MoS2 modified PAO15 oils were prepared,and the fourball friction tester was used to compare the influence of the two morphologies of MoS2 on the tribological properties of PAO15 oil under different contents.The wear scar surface of the steel ball was characterized by optical microscope,surface profilometer,scanning electron microscope (SEM) and energy dispersive spectrometer (EDS).The results show that the prepared spherical and flowershaped MoS2 crystal forms are in line with the crystal form of MoS2,which can improve the tribological properties and reduce the friction coefficient of PAO15 oil.With the increase of the MoS2 particles added amount,the tribological performance of PAO15 oil is improved,and the optimal amount is mass fraction 1.0%.The flowershaped MoS2 has a larger specific surface area,and its antiwear performance in PAO15 oil is better than that of the spherical MoS2,the transfer film formed by it can better isolate the friction surface.