Carbon　nanotubes　(CNT)　are　widely　used　in　composites　because　of　their　excellent　mechanical　properties,　such　as　light　weight,　high　strength,　and　stable　chemical　properties.　In　order　to　explore　the　reasons　for　the　difference　in　mechanical　strengthening　effects　of　different　matrices,　in　this　paper,　quasi-static　tensile,　bending　tests　and　dynamic　impact　test　were　carried　out　on　CNT　composite　resin　matrix　and　aluminum　alloy　matrix,　and　the　reinforcement　mechanism　of　CNT　in　different　matrices　was　further　revealed.　The　results　show　that　CNT　could　effectively　improve　the　tensile　strength　and　energy　absorption　properties　of　resin　materials,　and　when　the　CNT　content　(mass　ratio)　was　0.7%,　the　reinforcement　effect　was　the　best.　For　aluminum　alloy,　the　addition　of　CNT　would　reduce　the　strength　of　the　material,　and　the　higher　the　content　of　CNT,　the　lower　the　tensile　strength　of　the　material.　The　essence　of　the　different　mechanical　strengthening　effects　of　metal　matrix　and　resin　matrix　after　adding　CNT　lied　in　the　different　interfacial　bonding　between　CNT　and　matrix.　The　initial　state　of　resin　matrix　was　liquid;　after　curing,　CNT　could　be　filled　in　the　matrix　network　gap,　so　as　to　enhance　the　mechanical　properties　of　materials;　the　aluminum　alloy　matrix　was　powder,　and　the　dispersion　of　mechanical　force　caused　CNT　damage,　and　the　existence　of　CNT　caused　the　gap　between　the　powders　to　become　larger,　weakening　the　mechanical　properties　of　the　material.　The　research　results　of　this　study　provide　a　theoretical　reference　for　subsequent　research　and　development　of　a　variety　of　matrix　particles　and　fiber-reinforced　composites.　©　2023　Beijing　Institute　of　Technology.　All　rights　reserved.