Palladium-catalyzed　Suzuki-Miyaura　cross-coupling　reaction　is　a　powerful　route　to　construct　carbon-carbon　bonds　in　fine-chemical　synthesis.　However,　the　activation　of　relatively　chemically　inert　aryl　chlorides　under　mild　conditions　in　this　reaction　is　still　a　great　challenge.　Herein,　N-doped　hollow　carbon　nanosheet　assemblies　(HCNAs)　were　first　developed　by　hydrothermal　carbonization　of　glucose　through　an　in　situ　self-generating　template　method,　and　the　corresponding　Pd　single-atom　catalyst　(Pd-1/HCNAs)　fabricated　by　a　conventional　deposition-precipitation　method　showed　superior　catalytic　activity　(TOFs　=　499　h(-1))　and　high　stability　for　the　Suzuki　coupling　reaction　of　chlorobenzene　under　mild　condition.　Characterizations　of　transmission　electron　microscopy,　electron　paramagnetic　resonance　spectroscopy,　Raman　spectra,　X-ray　absorption　spectroscopy,　and　X-ray　photoelectron　spectroscopy　showed　that　the　high　catalytic　activity　and　stability　of　Pd-1/HCNAs　were　related　with　its　full　positively　charged　Pd　single-atom　active　sites　and　the　low　reducibility　of　Pd　atom　due　to　the　strong　interaction　between　Pd　atom　and　the　HCNA　carrier.　Meanwhile,　the　relative　high　chlorobenzene　and　phenylboric　acid　adsorption　and　the　low　affinity　to　product　biphenyl　as　well　as　the　special　three-dimensional　structure　of　Pd-1/HCNAs　were　also　beneficial　to　improve　the　catalytic　activity.