Poly(acrylamide)　(PAM)　has　excellent　thickening　ability　as　a　conventional　flooding　agent.　However,　PAM　confronts　the　problems　of　high　injection　pressure　and　high　shear　loss　in　the　process　of　oil　extraction,　which　have　limited　its　application　in　this　field.　In　this　work,　2,　2,　6,　6-Tetramethylpiperidinooxy　oxidized　cellulose　nanofibers　(TOCNFs)　enhanced　sodium　alginate　(SA)　shell　was　used　to　encapsulate　PAM　to　form　microcapsule.　The　composition,　morphology,　structure　and　the　releasing　behaviours　of　TOCNFs　enhanced　microcapsules　was　tested.　Mechanical　stirring　was　used　to　simulate　the　state　of　polymer　subjected　to　shear　during　stratigraphic　transport.　The　release　performance　of　the　microcapsules　was　characterized　by　measuring　the　change　of　viscosity　with　time.　The　ratio　of　the　shell　material　with　the　best　performance　was　explored,　and　the　enhancement　mechanism　of　the　SA　shell　by　TOCNFs　was　discussed.　The　experiments　showed　that　the　release　time　of　PAM　from　the　microcapsules　was　significantly　prolonged　with　the　addition　of　TOCNFs.　The　longest　release　time　was　observed　when　the　ratio　of　SA　and　TOCNFs　was　5:　1,　with　the　release　time　of　the　microcapsules　from　the　original　8　h　to　16　h.　The　enhanced　shear　resistance　of　the　microcapsules　was　attributed　to　the　semi-interpenetrating　network　structure　of　SA　and　TOCNFs　via　Ca2+　cross-linking　as　well　as　hydrogen　bonding.　The　prepared　microcapsules　have　promising　applications　in　enhancing　oil　recovery.　©　2024　Elsevier　B.V.