Electrochemical　water　splitting　to　prepare　hydrogen,　including　hydrogen　evolution　reaction　(HER),　is　considered　as　one　of　the　green　and　practical　approaches　for　the　wide　application　of　new　energy　sources.　During　this　process,　efficient　catalyst　is　essential　to　hydrogen　production　efficiency.　Wherein,　nickel–cobalt　complex　sulfides　(CoS@NiS)　with　few　layers　and　large　contact　area　is　an　emerging　cost-effective　catalyst　for　hydrogen　production.　However,　traditional　hydrothermal　synthesis　process　implemented　in　the　stirred　tank　reactor,　because　of　its　low　heat　and　mass　transfer　efficiency,　resulted　in　long　reaction　time　and　high　energy　consumption,　limiting　the　scale-up　production　and　synthesis　efficiency.　In　this　work,　an　efficient　continuous　synthesis　platform　based　on　microreactor　was　designed　to　prepare　high-performance　and　few-layer　CoS@NiS　nanosheets　with　porous　structure　of　petaloid　clusters　and　wrinkled　defects　edge.　By　optimizing　experimental　conditions,　the　prepared　CoS@NiS　nanosheets　exhibited　excellent　electrocatalysis　performance　for　HER　with　low　overpotential　of　157　mV　at　10　mA·cm−2,　small　Tafel　slope　of　75.9　mV·dec-1　and　long-term　catalytic　stability.　It　was　worth　noting　that　the　HER　activity　of　CoS@NiS　nanosheets　obtained　in　continuous　flow　platform　within　20　min　was　higher　than　that　in　the　traditional　stirred　tank　reactor　over　12　h　(182　mV　at　10　mA·cm−2　and　93.3　mV·dec-1),　significantly　improving　the　synthesis　efficiency.　The　continuous　flow　synthesis　platform　provides　an　efficient　and　convenient　solution　for　the　scale-up　production　of　high-performance　electrocatalytic　nanomaterials.　©　2024