The　tribological　properties　of　polyaromatic　organics　(xPyE)　as　lubricating　grease　additives　are　studied　by　simulations　and　experiments.　Molecular　Dynamics　(MD)　simulations　are　used　to　simulate　the　mechanical　properties　of　four　kinds　of　polyaromatic　organics　(2P1E,　3P2E,　4P3E,　and　5P4E)　with　different　aromatic　ring　numbers　and　a　mass　fraction　under　300　MPa　and　5　m/s　relative　shear　velocity　of　the　two　solid　walls.　The　friction　force,　positive　pressure,　stress,　and　adsorption　energy　are　calculated　quantitatively.　Meantime,　the　friction　coefficient　of　lubricating　grease　and　the　wear　morphology　of　the　sample　are　measured　by　Multifunctional　Friction　and　Wear　Testing　Machine.　The　results　show　that　the　organic　additives　adsorbed　on　the　wall　form　a　protective　film　during　the　shearing　process,　improving　the　bearing　capacity　and　reducing　friction　and　wear.　Among　them,　the　3P2E　organic　additive　has　an　appropriate　number　of　aromatic　rings.　Its　single　molecular　adsorption　energy　and　unit　adsorption　energy　are　higher　than　other　organic　additives　and　can　uniformly　lay　on　the　wall　to　form　a　stable,　protective　film.　This　demonstrates　the　best　friction　performance　and　improves　the　load-bearing　capacity　of　the　lubricating　film,　reducing　maximum　wall　stress　by　53.4　%.　©　2024　Elsevier　B.V.