The　effects　of　MoS2　and　MoS2　modified　by　adding　oleic　acid　(OA)　on　the　friction　properties　of　lithium-based　grease　under　boundary　lubrication　conditions　are　studied　by　molecular　dynamics　(MD)　simulation　and　experiment.　A　rough　wall　boundary　lubrication　MD　model　with　peaks　and　grooves　is　established　to　simulate　the　mechanical　properties　and　lubrication　effects　of　three　lubrication　systems　on　rough　walls　for　the　relative　shear　velocity　between　the　two　solid　walls　of　5　m/s　at　500　MPa.　The　stress,　wear　amount,　friction　force,　normal　pressure,　and　friction　heat　of　the　friction　surface　are　quantitively　calculated.　Simultaneously,　a　Retc　friction　and　wear　testing　machine　is　used　to　measure　the　friction　coefficient　under　different　concentrations　of　additives　and　different　pressures.　The　results　show　that　the　grease　added　with　MoS2　can　reduce　friction,　wear,　and　the　temperature　between　friction　pairs.　However,　under　high　pressure　and　shear,　MoS2　can　easily　agglomerate　and　accumulate　in　the　pits,　reducing　the　lubricating　effect.　At　the　same　time,　since　OA-modified　MoS2　can　reduce　agglomeration,　the　modified　MoS2　is　adsorbed　on　the　metal　wall　surface,　forming　a　stable　lubricant　film.　The　main　contributions　of　this　article　can　be　found　in　combining　MD　simulation　and　experimentation,　establishing　the　connection　between　micronano　structures　and　macroscopic　properties,　exploring　the　mechanism　of　the　influence　of　wall　roughness　and　particle　size　on　the　friction　performance　of　lubricating　oil,　and　providing　a　theory　for　predicting　and　developing　high-performance　new　lubricating　grease.