The　maintenance　relationship　network　for　the　components　of　high　speed　railway　has　been　demonstrated　a　complex　relationship　network.　Based　on　this　and　according　to　the　reliability　theory　of　complex　network,　the　node　betweenness　and　node　agglomeration　in　the　invulnerability　index　of　complex　network　were　regarded　as　the　indices　to　evaluate　the　importance　of　the　components　for　high　speed　train　system　and　analyze　the　connectivity　in　the　local　networks　of　the　system.　In　this　way,　the　important　components　and　redundancy　deficient　ones　were　selected,　which　provided　new　ideas　for　the　further　reliability　study　of　the　components　for　high　speed　train.　Taking　the　traction　system　of　CRH3　high　speed　train　as　a　case　study,　the　results　show　that　the　calculation　method　based　on　the　reliability　of　complex　network　can　correctly　select　the　important　and　redundancy　deficient　components　in　the　system,　which　provides　scientific　basis　for　the　follow-up　system　reliability　design　and　redundancy　design　accordingly.