Friction　and　wear　reduction　are　widely　sought　to　promote　energy　savings　and　reliability　of　moving　machine　components.　Here,　a　combination　of　MST2　experiments　and　molecular　dynamics　(MD)　simulations　unveils　the　detailed　lubrication　mechanisms　and　presents　quantitative　wear　descriptions　of　Cu　and　Fe　nanoparticle　(NP).　The　MD　simulations　results　indicate　that　average　value　of　friction　force　is　reduced　approximately　57.15%　after　the　addition　of　Cu　NP　and　these　results　is　similar　to　the　experimental　results.　In　addition,　bimetallic　CuFe　NP　(Cu–Fe　or　Cu@Fe　NP)　shows　superior　performance　than　pure　Cu　NP,　and　the　tribological　properties　of　bimetallic　CuFe　NP　change　with　structures.　Bimetallic　CuFe　NP　can　be　prepared　and　investigated　by　experimental　methods,　but　the　effects　of　different　structures　of　bimetallic　CuFe　NP　on　lubrication　are　not　sufficiently　studied.　The　superior　structure　of　bimetallic　CuFe　NP　with　higher　load-carrying　capacity　and　better　tribological　properties　is　predicted　by　MD　simulations.　Results　from　simulations　suggest　that　there　is　an　optimal　NP　structure　and　size　that　will　minimize　friction　and　wear　for　a　given　surface　roughness.　©　2022　Elsevier　B.V.