Seawater　reverse　osmosis　(SWRO)　technology　has　been　universally　adopted　because　of　its　high　efficiency,　economic　benefits,　easy　maintenance,　and　high-pressure　seawater　pump　(HPSP)　and　energy　recovery　device　(ERD)　are　essential　components,　which　determine　the　specific　energy　consumption　of　SWRO　system.　However,　it　is　still　unclear　about　energy　dissipation　mechanism　and　mixing　characteristics　from　the　perspective　of　system.　For　that,　this　thesis　proposes　a　novel　system-level　Computational　Fluid　Dynamics　(CFD)　model　considering　all　interfaces　in　HPSP　and　integrated　energy　recovery　and　pressure　boost　device　(IERPBD).　To　profoundly　investigate　the　system　performance　under　various　operating　conditions,　the　pressure　and　composition　distribution,　power　loss　of　each　interface　and　mixing　rate　are　numerically　calculated　and　analyzed.　Additionally,　experiment　of　the　effect　of　temperature　on　SWRO　system　performance　is　conducted　to　practically　verify　the　proposed　model,　which　indicates　that　the　presented　model　could　precisely　reflect　the　energy　dissipation　and　mixing　characteristics.　Besides,　it　is　advised　that　the　rotating　speed　of　HPSP　and　IERPBD　should　not　be　set　too　high　which　could　increase　the　mixing　rate　and　energy　consumption,　and　higher　temperature　might　lower　the　quality　of　produced　freshwater.　This　study　offers　a　feasible　way　to　reveal　the　energy　dissipation　mechanism　of　SWRO　desalination　system.