To　investigate　the　impact　of　combined　temperature　and　humidity　curing　conditions　on　the　failure　modes　and　delamination　mechanisms　of　carbon　fiberreinforced　polymer　(CFRP)-bonded　steel　interfaces,　this　study　conducted　double-shear　bonding　tests　on　CFRP-steel　composites,　considering　multiple　factors　such　as　temperature,　humidity,　bonding　length,　and　adhesive　layer　thickness.　The　influence　on　the　interfacial　bonding　performance　of　CFRP-steel　interfaces　was　analyzed　comprehensively,　and　the　axial　strain　distribution　of　CFRP　during　static　tensile　processes　was　monitored　using　3D-DIC　technology.　The　findings　reveal　that　peak　bonding　load　is　higher　under　curing　conditions　of　60℃　and　60%　relative　humidity,　whereas　low　temperature　and　high　humidity　environments　are　more　prone　to　cause　failure　at　the　steel-adhesive　interface.　Both　increased　temperature　and　humidity　resulted　in　a　reduction　in　interfacial　shear　stress　peak　values　and　an　increase　in　slip,　illustrating　the　impact　of　temperature　and　humidity　on　the　ductility　and　adhesive　properties　of　the　interface.　Additionally,　it　was　found　that　an　increase　in　bonding　length　helps　disperse　stress　across　a　wider　area,　and　a　thinner　adhesive　layer　contributes　to　higher　interfacial　shear　stress　peaks　and　improved　stress　distribution.　Lastly,　based　on　the　experimental　data,　a　simplified　trilinear　shear-slip　model　was　derived　using　the　smoothing　method,　providing　theoretical　support　and　design　reference　for　the　engineering　application　of　CFRP-reinforced　steel　structures.　©　2025　Beijing　University　of　Aeronautics　and　Astronautics　(BUAA).　All　rights　reserved.