Steel　lazy-wave　riser　(SLWR)　is　one　of　the　key　technical　components　of　offshore　oil-gas　production　systems　and　is　widely　utilized　in　deepwater　areas.　On　the　basis　of　the　vector　form　intrinsic　finite　element　(VFIFE)　method,　this　study　develops　a　reasonable　numerical　model　for　the　SLWR　to　investigate　the　effects　of　the　buoyancy　section　on　its　mechanical　characteristics.　In　the　SLWR　model,　the　buoyancy　section　is　simulated　using　an　equivalent　riser　segment　with　the　same　outer　diameter　and　unit　weight.　The　riser　is　considered　to　be　composed　of　a　series　of　space　vector　particles　connected　by　elements,　and　virtual　reverse　motions　are　applied　to　establish　the　fundamental　equations　of　forces　and　displacements.　The　explicit　central　difference　technique　is　used　to　solve　the　governing　equations　for　particle　motion　within　the　riser　through　programming　implementation.　To　provide　a　detailed　explanation　of　the　process　by　which　the　SLWR　achieves　a　stable　lazy-wave　configuration,　a　numerical　model　of　a　2800-m-long　riser　is　established　at　a　water　depth　of　1600　m,　and　the　feasibility　of　this　model　for　riser　behavior　analysis　is　validated.　The　remarkable　influences　of　the　position,　length,　number　and　spacing　of　the　buoyancy　section　on　the　mechanical　behavior　of　the　SLWR　are　observed,　which　provides　a　theoretical　foundation　for　the　optimal　design　of　the　SLWR　in　deepwaters.　©　Chinese　Ocean　Engineering　Society　and　Springer-Verlag　GmbH　Germany,　part　of　Springer　Nature　2025.