A　simulated　electrocatalytic　nanosystem　of　MoC@NG　assembled　nanosheet　is　successfully　constructed　by　a　thermolysis　procedure　and　first　applied　in　piezocatalytic　H2　production　from　pure　water.　Owing　to　the　unique　configuration　of　MoC　quantum　dots　(QDs)　encapsulated　in　ultrathin　N-doped　graphene　(NG)　vesicles　(MoC@NG),　both　the　aggregation　of　MoC　QDs　and　stack　of　ultrathin　NG　layers　in　MoC@NG　are　suppressed　simultaneously.　When　the　integration　is　subjected　in　mechanical　vibration,　ultrathin　NG　layers　can　provide　piezoelectric　potential　to　trigger　hydrogen　evolution　reaction　(HER)　on　MoC　QDs,　while　MoC　QDs　could　not　only　collect　free　electrons　to　achieve　the　carriers’　intercomponent　separation,　but　also　provide　rich　and　high-activity　HER　sites　with　lower　overpotential.　The　rate　of　piezocatalytic　H2　production　from　H2O　is　as　high　as　1.690　μmol　h−1　mg−1,　which　is　the　reported　highest　H2　evolution　rate　of　piezocatalytic　water　splitting　without　any　sacrificial　agents,　even　higher　than　ones　in　many　photocatalytic　pure　water　splitting　systems.　It　is　the　synergy　of　piezoelectric　ultrathin　NG　layers　and　conductive　MoC　QDs　that　predominantly　contributes　to　a　superhigh　piezocatalytic　performance.　Furthermore,　this　design　concept　is　expected　to　break　a　new　ground　in　piezocatalysis.　©　2020　Elsevier　Ltd