Aiming　at　the　problem　of　weak　interfacial　binding　force　between　the　absorbent　microcapsule　(SA)　with　calcium　alginate　as　shell　and　epoxy　resin　E-51　as　core　and　cement　matrix,　silane　coupling　agent　was　used　to　modify　the　surface　of　SA　microcapsule　to　improve　its　interfacial　binding　with　cement　matrix,　so　as　to　improve　the　self-healing　effect.　By　means　of　SEM,　microhardness　and　drawing　test,　the　interface　bonding　was　analyzed　from　micro,　mesoscopic　to　macro　scale,　and　the　self-healing　effect　was　evaluated　by　the　recovery　rate　of　compressive　strength　and　water　permeability　resistance　of　the　mortar　specimen　after　damage　repair.　The　results　show　that　the　interface　bond　between　SA　and　cement　matrix　is　closer　after　modification　with　coupling　agent　KH792,　the　microhardness　at　the　interface　is　increased　by　159%,　and　the　interface　bond　strength　is　increased　by　67%.　For　the　mortar　mixed　with　4wt%　(cement　mass)　SA,　the　compressive　strength　recovery　rate　after　load　damage　is　103%,　and　the　seepage　resistance　recovery　rate　after　water　pressure　damage　is　118%.　The　surface　modification　of　silane　coupling　agent　significantly　improved　the　interface　bonding　between　SA　and　cement　matrix,　and　the　self-healing　effect　of　cement-based　materials　was　enhanced.　©　2025　Beijing　University　of　Aeronautics　and　Astronautics　(BUAA).　All　rights　reserved.