Compared　with　traditional　membrane　distillation　system,　the　heat　pump　two-effect　direct　contact　membrane　distillation　system　has　an　advantage　of　low　energy　consumption.　However,　affected　by　many　kinds　of　parameters,　such　as　materials,　components　and　operation　conditions　as　well　as　the　complex　coupling　between　these　parameters,　it　is　difficult　to　achieve　the　optimal　operation　conditions　and　high　gained　output　ratio　(GOR)　by　optimizing　the　parameters.　Therefore,　analyses　of　mathematical　modeling　and　optimal　operation　conditions　of　heat　pump　two-effect　direct　contact　membrane　distillation　system　were　carried　out　in　this　paper.　According　to　the　operating　principle　and　physical　characteristics　of　key　components,　such　as　membrane　distillation　system,　heat　pump　system,　intermediate　heat　exchanger　and　auxiliary　cooler,　the　mathematical　model　of　heat　pump　two-effect　direct　contact　membrane　distillation　system　was　established,　the　process　of　system　performance　simulation　was　designed　and　system　performance　simulation　software　was　compiled　to　analyze　the　effect　of　ten　parameters　on　GOR　and　total　water　production(Wtot).　The　optimal　operation　conditions　analysis　method　of　heat　pump　two-effect　direct　contact　membrane　distillation　system　was　proposed.　Through　the　developed　simulation　software　of　the　heat　pump　membrane　distillation　system,　using　the　proposed　optimal　operation　conditions　analysis　method,　When　Wtot　was　10.0kg/h　and　heat　pump　compressor　power　was　688W,　the　GOR　of　the　optimized　system　could　reach　9.43　©　Published　under　licence　by　IOP　Publishing　Ltd.