Superhydrophobic　conductive　materials　have　received　a　great　amount　of　interest　due　to　their　wide　applications　in　oil-water　separation,　electrically　driven　smart　surface,　electromagnetic　shielding,　and　body　motion　detection.　Herein,　a　highly　conductive　superhydrophobic　cotton　cloth　is　prepared　by　a　facile　method.　A　layer　of　polydopamine/reduced　graphene　oxide　(PDA/rGO)　was　first　coated　on　the　cotton　fabric,　and　then　copper　nanoparticles　were　in　situ　grown　on　the　prepared　surface.　After　further　modification　with　stearic　acid　(STA),　the　wettability　of　the　cotton　surface　changed　from　superhydrophilic　to　superhydrophobic　(water　contact　angle　(WCA)　=　153°).　The　electrical　conductivity　of　the　PDA/rGO/Cu/STA　cotton　is　as　high　as　6769　S·m-1,　while　the　stearic　acid　effectively　protects　Cu　NPs　from　oxidation.　As　a　result,　the　superhydrophobic　PDA/rGO/Cu/STA　cotton　has　shown　excellent　electrical　stability　and　can　be　used　in　detecting　human　motions　in　both　ambient　and　underwater　conditions.　The　sensor　can　recognize　human　motion　from　air　into　water　and　other　underwater　activities　(e.g.,　underwater　bending,　stretching,　and　ultrasound).　This　multifunctional　cotton　device　can　be　used　as　an　ideal　sensor　for　underwater　intelligent　devices　and　provides　a　basis　for　further　research.　©