Graphene-based　membranes　have　been　considered　as　promising　separation　membranes　for　water　treatments　due　to　their　unique　two-dimensional　confined　channels.　However,　subject　to　the　preparation　technology,　the　effective　construction　of　graphene-based　filtration　membranes　with　suitable　separation　ability　on　heavy　metal　ions　still　face　considerable　challenges.　Herein,　we　have　successfully　constructed　a　kind　of　graphene-based　(reduced　graphene　oxide,　rGO)　nanofiltration　membranes　by　adopting　a　plasma-assisted　in-situ　photocatalytic　reduction　method.　Graphene　oxide-Ag　(GO-Ag)　composite　sheets　are　prepared　firstly　and　then　assembled　into　membranes　by　vacuum　filtration.　With　the　use　of　Ag　nanoparticles　as　plasmonic　photocatalyst,　GO-Ag　films　can　be　in-situ　reduced,　leading　to　the　formation　of　rGO-based　composite　membranes.　Thanks　to　the　mild　in-situ　reduction　process,　the　filtration　ability　on　heavy　metal　ions　(Cr(VI),　Cr3+,　Cu2+　and　Pb2+)　caused　by　lamellar　structure　is　well　retained　in　the　as-formed　rGO-Ag　membranes.　Especially,　when　treating　the　typical　toxic　Cr(VI)　solution,　the　retention　capacity,　water　flux　and　stability　of　rGO-Ag　membranes　are　all　improved　compared　with　that　of　the　original　GO-Ag　ones.　In　addition,　the　effectively　rejection　of　Cr(VI)　from　mixed　solutions　containing　both　Cr(VI)　and　Cr(III)　also　suggests　the　good　applicability　of　such　rGO-Ag　membranes　in　a　complex　wastewater　system.