The　Internet　of　Vehicles　is　a　multi-trust　domain　autonomous　network　designed　to　provide　real-time　and　reliable　message　services　for　vehicles,　including　road　conditions,　path　planning,　etc.　However,　due　to　factors　such　as　the　rapid　movement　of　vehicle　nodes,　frequent　network　access,　and　uneven　distribution　of　vehicle　nodes,　rapid　cross-domain　message　authentication　has　become　an　important　challenge.　In　order　to　enhance　the　security　of　cross-domain　authentication　in　the　Internet　of　Vehicles,　this　paper　proposes　a　secure　authentication　key　management　protocol.　In　this　protocol,　the　current　domain＇s　edge　server　comprehensively　evaluates　the　vehicle　by　combining　the　real-time　information　of　the　vehicle　and　the　information　of　the　domains　it　has　passed　before.　Once　the　assessment　is　qualified,　the　vehicle,　with　the　assistance　of　TA,　completes　the　establishment　of　session　keys　to　achieve　secure　communication.　This　article　uses　BAN　logic　to　formally　prove　the　security　of　the　protocol　and　analyzes　its　performance　through　network　simulation　tools.　Experimental　results　demonstrate　that　the　proposed　scheme　significantly　improves　security　and　performs　well　in　terms　of　network　performance.