Water-based　graphene-copper　composite　conductive　paste　was　prepared　using　water-based　carrier　instead　of　organic　carrier,　inwhich,　mixed　copper　powder　with　particle　size　of　5　and　15　μm　as　mainly　conductive　phase　and　a　small　amount　of　graphene　as　conductive　reinforcement　phase.　The　effect　of　water-based　carrier　on　the　paste　performance　was　studied　by　four-probe　tester　and　scanning　electron　microscope(SEM).　The　possible　conductive　mechanism　of　water-based　graphene-copper　composite　conductive　paste　was　discussed　and　the　conductive　connection　model　was　established.　The　results　show　that　the　prepared　water-based　carriers　have　better　performance　when　m(deionized　water)msodium　carboxymethyl　cellulose　(CMC)mpolyethylene　glycol　(PEG)m(defoamer)　being　96.91.51.50.1.　When　the　content　of　water-based　carrier　is　30%　(mass　fraction),　the　prepared　water-based　graphene-copper　composite　conductive　paste　has　excellent　printing　performance　and　a　small　electrical　resistivity　of　1.65　mΩ•cm.　The　resistivity　of　water-based　composite　paste　with　graphene　is　97.1%　lower　than　that　of　pure　copper　paste,　and　75.78%　lower　than　that　of　graphene-copper　composite　paste　prepared　with　organic　carrier.　The　prepared　conductive　film　is　flatter　and　denser,　and　the　contact　between　conductive　phases　is　more　compact.　A　large　number　of　graphene　overlaps　laterally　or　fills　radially　the　gap　between　copper　powders,　forming　conductive　channels　in　parallel　or　in　series　with　copper　powders　and　forming　a　dense　conductive　network,　thus　improving　the　conductivity　of　the　composite　paste.　©　2020,　Editorial　Office　of　FINE　CHEMICALS.　All　right　reserved.