As　a　novel　energy　conversion　device,　free　piston　linear　generator　(FPLG)　has　high　potential　for　organic　Rankine　cycle　(ORC)　system.　In　this　study,　a　FPLG　simulation　model　has　been　established　and　the　accuracy　is　verified,　then　the　ORC-FPLG　combined　system　simulation　model　is　established　for　the　first　time.　The　performance　study　and　parameter　analysis　has　been　performed.　The　results　show　that　the　simulation　results　are　consistent　with　the　experiments,　all　the　relative　errors　are　in　the　range　of　+/-　10%,　which　indicates　the　accuracy　of　FPLG　simulation　model.　The　operation　parameters　(such　as　speed,　operation　frequency　and　condenser　temperature)　have　significant　influence　on　the　ORC-FPLG　combined　system.　The　lower　the　pump　speed　is,　the　higher　the　maximum　power　output　and　minimum　power　input　are.　The　net　power　output　of　combined　system　increases　with　operation　frequency,　exhaust　temperature,　exhaust　mass　flow　rate　and　cooling　water　flow　rate.　Thermal　efficiency　decreases　with　condenser　temperature　and　pump　speed.　There　exists　an　optimal　operation　frequency　achieving　the　maximum　net　power　output.　When　operation　frequency　is　16　Hz,　the　maximum　value　of　net　power　output　and　thermal　efficiency　can　reach　up　to　2.26　kW　and　1.72%.