In order to obtain the preparation process of nano molybdenum disulfide with high yield and good reproducibility,a controllable hydrothermal preparation method of nano molybdenum disulfide was proposed.With sodium molybdate and thioacetamide as precursors,respectively with polyethylene glycol (PEG20 000),hexadecyl trimethyl ammonium chloride (CTAC),anhydrous ethanol as surfactant,sphere and flower molybdenum disulfide nanoparticles were prepared by hydrothermal method.By Xray diffraction (XRD),scanning electron microscope (SEM),the characteristics of the product were characterized.And the extreme pressure property test of 2% nano molybdenum disulfide in N46 lubricating oil was carried out by fourball friction and wear tester.The results show that in the acidic conditions,when adding surfactant PEG20 000 and CTAC,the sphere structure of molybdenum disulfide nanoparticles with uniform particle size of about 100 nm can be obtained;when adding surfactant anhydrous ethanol,the flower structure of molybdenum disulfide nanoparticles,with particle size of 190 nm in sulfuric acid environment and 70 nm in hydrochloric acid environment,can be obtained.In sulfate environment,the yield of molybdenum disulfide is the highest when polyethylene glycol is used as surfactant,which can be up to 7882%.Prepared nanospherical molybdenum disulfide as lubricating oil additives significantly improves the extreme pressure properties of lubricating oil.As compared with comercial molybdenum disulfide,the maximum nonseizure load can be increased about 42% at most.