The　carbon　dioxide　spillover　effects　and　influencing　factors　of　the　“Belt　and　Road　Initiative”　(BRI)　in　African　countries　must　be　assessed　to　evaluate　the　effectiveness,　promote　low-carbon　transmissions　in　African　countries,　and　provide　recommendations　for　achieving　the　2030　Sustainable　Development　Goals.　This　novel　study　employs　carbon　dioxide　emission　intensity　(CEI)　and　per　capita　carbon　dioxide　emissions　(PCE)　as　dual　indicators　to　evaluate　the　spatial　spillover　effects　of　54　BRI　African　countries　on　their　neighboring　countries’　carbon　emissions　from　2007　to　2023.　It　identifies　the　key　factors　and　mechanisms　affecting　these　spillover　effects　using　the　spatial　differences-in-differences　(SDID)　model.　Results　indicate　that　since　the　launch　of　the　BRI,　the　CEI　and　PCE　of　BRI　African　countries　have　significantly　increased,　largely　due　to　trade　patterns　and　industrialization　structures.　Greater　trade　openness　has　further　boosted　local　economic　development,　thereby　increasing　carbon　dioxide’s　spatial　spillover.　Government　management　and　corruption　control　levels　show　some　heterogeneity　in　the　spillover　effects,　which　may　be　attributed　to　long-standing　issues　of　weak　institutional　enforcement　in　Africa.　Overall,　this　study　reveals　the　complex　relationship　between　BRI　African　economic　development　and　environmental　outcomes,　highlighting　the　importance　of　developing　sustainable　development　strategies　and　establishing　strong　differentiated　regulatory　regimes　to　effectively　address　environmental　challenges.　©　2025　by　the　authors.