Recently,　solar-driven　interfacial　evaporation　(SDIE)　has　been　developed　quickly　for　low-cost　and　sustainable　seawater　desalination,　but　addressing　the　conflict　between　a　high　evaporation　rate　and　salt　rejection　during　SDIE　is　still　challenging.　Here,　a　spatial　confinement　strategy　is　proposed　to　prepare　the　gel　composite　solar　evaporator　(SCE)　by　loading　one　thin　hydrogel　layer　onto　the　skeleton　of　a　carbon　aerogel.　The　SCE　retains　the　hierarchically　porous　structure　of　carbon　aerogels　with　an　optimized　water　supply　induced　by　dual-driven　forces　(capillary　effects　and　osmotic　pressure)　and　takes　advantage　of　both　aerogels　and　hydrogels,　which　can　gain　energy　from　air　and　reduce　water　enthalpy.　The　SCE　has　a　high　evaporation　rate　(up　to　4.23　kg　m-2　h-1　under　one　sun)　and　excellent　salt　rejection　performance　and　can　maintain　structural　integrity　after　long-term　evaporation　even　at　high　salinities.　The　SDIE　behavior,　including　heat　distribution,　water　transport,　and　salt　ion　distribution,　is　investigated　by　combining　theoretical　simulations　and　experimental　results.　This　work　provides　new　inspiration　and　a　theoretical　basis　for　the　development　of　high-performance　interfacial　evaporators.　The　spatially　confined　hydrogel-modified　interfacial　evaporator　(SCE)　is　prepared　in　this　study.　Dual-driven　forces　for　water　transportation　of　SCE　including　capillary　effect　and　osmotic　pressure　ensure　sufficient　water　supply　for　continuous　evaporation　up　to　4.23　kg　m-2　h-1　under　one　sun　and　excellent　salt　rejection　performance　that　it　can　work　in　20　wt.%　saltwater　stably　for　the　long　term.　image