Hydrogen　(H2)　is　an　important　clean　energy　carrier　due　to　the　merits　of　high　combustion　value　and　zero-carbon　emission.　Water　electrolysis　has　been　regarded　as　a　promising　technology　for　achieving　green　and　sustainable　production　of　H2.　However,　most　of　the　electrocatalysts　for　water　splitting　can　only　work　at　low　current　density　with　poor　long-term　durability,　and　it　is　difficult　to　meet　the　extensive　requirements　of　industrial-scale　applications.　In　this　article,　challenges　including　the　charge　transfer,　mass　diffusion,　and　catalyst　stability　during　high-current-density　water　electrolysis　are　discussed.　With　the　aim　of　addressing　these　issues,　various　electrocatalyst　design　strategies　including　morphology　engineering,　electronic　structure　modulation,　and　surface/interface　engineering　are　summarized　in　detail.　For　the　purpose　of　promoting　practical　applications,　recent　achievements　of　practical　anion　exchange　membrane　water　electrolysis　(AEMWE)　and　proton　exchange　membrane　water　electrolysis　(PEMWE)　technologies　are　discussed.　Finally,　outlooks　toward　future　investigations　on　high-current-density　water　electrolysis　are　presented.　It　is　believed　that　this　review　will　guide　the　rational　design　of　catalysts　with　both　high　activity　and　high　stability　for　high-current-density　water　electrolysis,　and　promote　the　development　of　industrial-scale　green　H2　production.　Challenges　and　design　strategies　of　electrocatalysts　for　high-current-density　water　electrolysis.