Border　Gateway　Protocol　(BGP),　as　the　standard　inter-domain　routing　protocol,　is　a　distance-vector　dynamic　routing　protocol　used　for　exchanging　routing　information　between　distributed　Autonomous　Systems　(AS).　BGP　nodes,　communicating　in　a　distributed　dynamic　environment,　face　several　security　challenges,　with　trust　being　one　of　the　most　important　issues　in　inter-domain　routing.　Existing　research,　which　performs　trust　evaluation　when　exchanging　routing　information　to　suppress　malicious　routing　behavior,　cannot　meet　the　scalability　requirements　of　BGP　nodes.　In　this　paper,　we　propose　a　blockchain-based　trust　model　for　inter-domain　routing.　Our　model　achieves　scalability　by　allowing　the　master　node　of　an　AS　alliance　to　transmit　the　trust　evaluation　data　of　its　member　nodes　to　the　blockchain.　The　BGP　nodes　can　expedite　the　trust　evaluation　process　by　accessing　a　global　view　of　other　BGP　nodes　through　the　master　node　of　their　respective　alliance.　We　incorporate　security　service　evaluation　before　direct　evaluation　and　indirect　recommendations　to　assess　the　security　services　that　BGP　nodes　provide　for　themselves　and　prioritize　to　guarantee　their　security　of　routing　service.　We　forward　the　trust　evaluation　for　neighbor　discovery　and　prioritize　the　nodes　with　high　trust　as　neighbor　nodes　to　reduce　the　malicious　exchange　routing　behavior.　We　use　simulation　software　to　simulate　a　real　BGP　environments　and　employ　a　comparative　experimental　research　approach　to　demonstrate　the　performance　evaluation　of　our　trust　model.　Compared　with　the　classical　trust　model,　our　trust　model　not　only　saves　more　storage　overhead,　but　also　provides　higher　security,　especially　reducing　the　impact　of　collusion　attacks.