Objective:　To　predict　the　influence　of　connecting　position　between　left　superior　vena　cava　(LSVC)　and　pulmonary　artery　on　bilateral　bidirectional　Glenn　(BBDG)　shunt　by　numerical　simulation.　Methods:　Firstly,　a　3D　anatomical　geometrical　model　was　reconstructed　by　the　medical　images　of　a　hypoplastic　left　heart　syndrome　(HLHS)　patient　with　LSVC.　Secondly,　based　on　haptic　deformations,　several　computational　models　were　virtually　generated,　and　computational　fluid　dynamics　(CFD)　numerical　simulations　were　conducted　using　finite　volume　method.　Finally,　hemodynamic　parameters　were　analyzed　and　evaluated.　Results:　Flow　recirculation　was　observed　in　the　pulmonary　artery　between　the　LSVC　and　right　superior　vena　cava　(RSVC).　The　diameter　of　RSVC　was　defined　as　D.　Varying　the　distance　between　LSVC　and　RSVC　from　2D　to　3.5D　resulted　in　the　least　energy　dissipation　at　3D　and　the　most　at　2D.　The　blood　flow　rate　ratios　of　left　pulmonary　artery　to　right　pulmonary　artery　(LPA/RPA)　ranged　from　0.65-1.11.　Conclusions:　Too　close　distance　between　LSVC　and　RSVC　would　bring　out　unfavorable　hemodynamic　distributions　and　consume　more　energy　in　the　treatment　of　BBDG　shunt.　This　study　is　of　significance　for　surgeons　to　evaluate　the　optimal　Fontan　options　in　the　treatment　of　HLHS　accompanied　by　LSVC.