Liquid　desiccant　dehumidification　systems　have　demonstrated　good　energy　savings　and　dehu-midification　effects　in　extremely　hot　and　humid　areas.　However,　to　improve　system　performance,　the　matching　problem　between　the　desiccant-regeneration　solution　recirculation　ratio　and　system　performance　has　not　been　thoroughly　investigated.　Therefore,　in　this　study,　we　constructed　a　liquid　desiccant　dehumidification　system　with　solution　recirculation　and　set　four　circulation　modes:　NS　mode　without　solution　recirculation,　CS　mode　with　only　desiccant　solution　recircu-lation,　RS　mode　with　only　regeneration　solution　recirculation,　and　CRS　mode　with　both　desiccant　and　regeneration　solution　recirculation.　The　orthogonal　test　method　was　used　to　determine　the　influence　of　solution　recirculation　on　the　evaluation　indicators,　and　multi-objective　optimization　of　the　major　parameters　under　the　four　circulation　modes　was　performed　based　on　the　NSGA-II　and　TOPSIS　algorithms.　The　results　showed　a　clear　conflict　between　the　moisture　removal　rate　(MRR)　and　energy　consumption　(Q).　In　extremely　hot　and　humid　areas,　a　high　air　flow　rate　is　suitable　for　use　in　the　regenerator　to　process　small-flow-rate　solutions　or　set　larger　sizes.　Under　typical　environmental　conditions,　it　is　recommended　to　set　up　a　liquid　desiccant　dehumidification　system　with　a　solution　recirculation　structure:　when　MRR　demand　is　high,　the　CS　mode　should　be　used,　where　MRR　is　6.72　g/s;　when　Q　demand　is　high,　the　RS　mode　should　be　used　where　Q　is　35.34　kW;　considering　both　MRR　and　Q　effects,　the　CRS　mode　should　be　used　where　unit　energy　consumption　moisture　removal　rate　is　0.1196　g/(s.kW).