In　a　liquid　desiccant　dehumidification　system,　the　setting　of　solution　recirculation　can　enable　the　reuse　of　a　portion　of　the　solution,　resulting　in　good　dehumidification　and　energy-saving　effects.　The　concentration　difference　between　the　concentrated　and　dilute　solutions　determines　the　dehumidification　effect　when　the　system　is　in　equilibrium.　Therefore,　the　influence　of　different　dehumidification-regeneration　solution　recirculation　ratios　(Cs,deh,　Cs,reg)　on　the　equilibrium　concentration　difference　of　the　system　is　crucial,　but　there　is　still　a　certain　gap　in　this　area　of　research.　To　fill　this　gap,　this　paper　constructs　a　liquid　desiccant　dehumidification　system　with　a　solution　recirculation　structure.　Based　on　the　characteristics　of　the　recirculation　structure,　solution　recirculation　is　divided　into　three　models:　DR　model　-　only　dehumidification　solution　recirculation　(Cs,reg　=0),　RR　model　-　only　regeneration　solution　recirculation　(Cs,deh　=0),　and　DRR　model　-　simultaneous　setting　of　dehumidification-regeneration　solution　recirculation.　A　mathematical　model　is　established　to　parameterize　the　equilibrium　concentration　difference　and　COP　of　the　system.　The　results　show　that　compared　with　the　single-cycle　model　(NR　model:　Cs,deh=　Cs,reg　=0)　of　traditional　liquid　desiccant　dehumidification　systems,　setting　up　a　solution　recirculation　structure　can　significantly　improve　the　COP　of　the　system:　The　maximum　COP　under　DR　model,　RR　model　and　DRR　model　are　6.6　times,　7.0　times　and　12.1　times　that　of　NR　model　respectively.　©　2024　SPIE.