Two-dimensional　(2D)　MXene-based　lamellar　membranes　play　transformative　roles　in　membrane　filtration　technology.　Their　practical　use　in　water　treatment　is　however　hindered　by　several　hurdles,　e.g.,　unfavorable　swelling　due　to　weak　interactions　between　adjacent　MXene　nanosheets,　tortuous　diffusion　pathways　of　layered　stacking,　and　the　intrinsic　aquatic　oxidation-prone　nature　of　MXene.　Herein,　nanoporous　2D/2D　heterostructure　membranes　are　elaborately　constructed　via　solution-phase　assembly　of　oppositely　charged　MXene　and　modified　layered　double　hydroxide　(MLDH)　nanosheets.　As　a　multifunctional　component,　positively　charged　holey　MLDH　nanosheets　were　first　tailor-made　to　serve　simultaneously　as　a　binder,　spacer　and　surface-modifier;　next　they　were　intercalated　into　negatively　charged　MXene　lamella　to　enhance　structural　stability　and　mass　transfer　of　membranes.　As　a　result,　the　as-prepared　MLDH@MXene　heterostructure　membranes　successfully　break　the　persistent　trade-off　between　high　permeability　and　selectivity　while　mitigating　the　common　drawbacks　in　2D　MXene-based　lamellar　membranes,　e.g.,　swelling　issues,　restacking　problems,　and　vulnerable　chemical　stability.　Noticeably,　at　an　operating　pressure　of　4　bar　and　a　feed　solution　of　100　ppm　of　Congo　red,　the　heterostructure　membranes　enable　a　threefold　jump　in　permeability　(332.7　±　20　L　m-2　h-1　bar-1)　when　compared　to　the　pristine　MXene　membrane　(119.3　±　18　L　m-2　h-1　bar-1),　and　better　operational　stability　without　compromising　the　rejection.　©　2023　The　Authors