The　synergistic　effect　of　2,2-dibromo-3-hypoazopropionamide　(DBNPA)　and　rhamnolipid　(RL)　on　the　corrosion　behavior　of　X80　pipeline　steel　in　solutions　containing　sulfate　reducing　bacteria　(SRB)　Desulfovibrio　bizertensis　SY-1　was　investigated.　The　results　showed　that　compared　with　a　sterile　solution,　the　mass　loss　and　pitting　depth　of　X80　pipeline　steel　significantly　increased　in　the　presence　of　Desulfovibrio　bizertensis　SY-1,　while　corrosion　product　FeS　was　detected　on　steel　surface.　However,　the　addition　of　DBNPA　effectively　inhibited　the　growth　of　planktonic　and　sessile　bacterial　cells,　thereby　retarding　the　corrosion　process　on　X80　pipeline　steel.　Notably,　when　150　mg/L　DBNPA　and　500　mg/L　RL　were　co-added　in　the　solution,　the　corrosion　rate　of　X80　pipeline　steel　decreased　by　77.8%　compared　to　that　in　the　SRB　(p　=　0.009)　containing　solution,　whilst,　by　50%　compared　to　that　in　the　SRB　containing　solution　with　addition　of　300　mg/L　DBNPA　alone.　Furthermore,　this　combination　also　led　to　an　approximately　84.7%　reduction　in　corrosion　current　density　even　after　15　days＇　immersion　compared　to　that　in　the　SRB　containing　solution,　and　about　20.5%　reduction　compared　to　that　in　the　SRB　containing　solution　with　addition　of　300　mg/L　DBNPA　alone.　Therefore,　these　findings　found　that　the　cooperative　addition　of　150　mg/L　DBNPA　and　500　mg/L　RL　can　effectively　inhibit　the　corrosion　of　X80　pipeline　steel　induced　by　Desulfovi-brio　bizertensis　SY-1.　The　results　may　provide　references　for　selecting　and　utilizing　biocides.　©　2024,　Chinese　Society　of　Corrosion　and　Protection.　All　rights　reserved.