The　wind　power　system　has　always　focus　on　the　problem　of　lightning　protection　of　wind　turbine　blades.　Because　of　the　increase　of　the　capacity　of　wind　turbines,　the　effective　height　of　the　wind　turbines　and　the　length　of　the　blades　also　increase　a　lot,　and　the　problem　of　the　lightning　protection　failure　of　the　existing　blade　lightning　protection　system　(LPS)　against　direct　lightning　strikes　has　become　prominent　as　well.　There　is　still　short　of　an　optimization　design　of　the　LPS　which　can　not　only　meet　engineering　requirements　but　receive　all　the　downward　lightning　leaders.　In　this　paper,　a　design　scheme　of　overlying　conductors　on　both　of　the　leading　edge　and　the　tailing　edge　outside　the　tip　of　the　blade　was　proposed　to　solute　the　delamination　damage　of　the　blades.　This　design　of　LPS　could　reduce　the　vicinal　electric　field　of　the　down　conductors,　and　reduce　the　probability　of　the　streamer　discharge　incept　from　the　down　conductor　as　well　as　the　discharge　incept　outside　the　laminate.　The　experimental　study　on　the　lightning　protection　performance　was　carried　out　under　lightning　and　switching　impulse　voltage.　The　experimental　results　showed　that　the　overlying　conductors　can　effectively　receive　the　downward　leader　to　protect　the　blade　from　being　penetrated　in　its　laying　range,　but　the　protection　efficiency　would　decline　sharply　when　the　downward　leader　developed　outside　the　laying　range.　The　covering　length　of　the　conductors　should　be　12%　of　the　total　length　of　the　wind　turbine　blade,　which　can　reduce　the　lightning　damage　by　90%　or　above.　©　2019　IEEE.