Pipeline　installation　into　deep　waters　puts　higher　demands　for　the　laying　design.　To　reveal　pipelay　parametric　effects　on　the　pipeline　dynamic　behaviours,　this　study　developed　a　dedicated　finite　element　model　(FEM)　for　deepwater　S-lay　system　in　light　of　OrcaFlex.　This　FEM　sufficiently　considered　the　clashing　contacts　between　the　pipeline　and　stinger　rollers　as　well　as　pipe-seabed　interactions.　The　effectiveness　of　the　FEM　was　validated　by　contrast　with　the　calculated　values　obtained　from　an　analytical　model.　A　group　of　real　sea　state　data　was　collected　from　a　pipeline　installation　project　in　the　LW3-1　gas　field.　Extensive　numerical　analyses　of　laying　pipelines　for　various　pipelay　parameters　were　carried　out　under　the　dynamic　excitations　of　surface　waves,　ocean　currents　and　induced　vessel　motions.　The　influences　of　water　depth,　effective　tension　fed　from　tensioners,　stinger　length,　pipe　diameter　and　submerged　self-weight　on　the　pipeline　dynamic　behaviours　were　systematically　evaluated.　A　strong　relevance　between　pipelay　parameters　and　pipeline　responses　was　observed,　which　could　provide　a　practical　reference　for　the　deepwater　installation　design.