Polymer　material　(PM)　is　a　novel　vertical　barrier　material,　demonstrated　to　be　effective　in　impeding　pollutants.　However,　the　associated　transport　research　is　limited.　This　study　aims　to　develop　an　analytical　solution　for　two-dimensional　transport　of　organic　contaminant　in　the　PM-enhanced　composite　cutoff　wall　(CCW)　system,　where　the　variable　substitution　and　Fourier　transform　methods　are　used.　This　analytical　solution,　available　in　various　simplifications,　is　effectively　validated　via　several　comparisons.　Following　this,　the　analyses　show　that　an　increase　in　the　non-uniformity　of　pollution　source　concentration　distribution　shortens　the　PM-enhanced　CCW＇s　breakthrough　time　(tb),　while　exhibits　a　marginal　effect　on　the　total　flux　at　its　exit.　The　increment　of　aquifer　horizontal　thickness　prolongs　the　tb　to　some　extent,　whereas　an　increase　in　its　hydraulic　conductivity　slightly　reduces　the　tb.　Additionally,　the　PM　layer　location　is　found　to　have　a　little　effect　on　the　PM-enhanced　CCW＇s　barrier　performance.　Furthermore,　the　equivalent　performance　assessment　reveals　that　the　improvement　gained　from　increasing　the　PM　layer　thickness　far　surpasses　that　from　increasing　the　single-layered　cutoff　wall　thickness,　and　this　difference　may　exceed　10.　For　a　PM　layer　with　low　hydraulic　conductivity,　it　is　more　suitable　for　engineering　scenarios　with　the　higher　hydraulic　head　difference.　Totally,　the　proposed　analytical　solution　offers　a　valuable　tool　for　designing　the　PM-enhanced　CCW.　©　2025　Elsevier　B.V.