With　the　increasing　application　of　carbon　fiber　reinforced　polymer　(CFRP)　in　steel　structure　engineering,　the　bond-slip　behavior　between　the　two　has　attracted　much　attention.　Firstly,　18　sets　of　CFRP　sheet-Q690qD　highstrength　steel　double　strap　shear　specimens　were　fabricated　considering　the　effects　of　CFRP　sheet　thicknesses　and　bond　length.　Then,　static　and　fatigue　tests　were　conducted　on　them.　Subsequently,　based　on　the　3D-DIC　acquisition　technology,　the　bond-slip　curves　were　obtained　using　the　smoothing　method　and　the　fitting　method　respectively　Finally,　the　three　key　parameters　of　tau(max),　s(1　)and　s(f)　in　the　bifurcated　model　at　each　working　condition　were　obtained.　The　experimental　results　indicated　that　the　bond　length　was　positively　correlated　with　the　static　load　ultimate　strength,　while　the　thickness　of　the　CFRP　sheet　had　less　effect　on　the　ultimate　strength.　The　fatigue　life　of　the　specimen　with　a　bond　length　of　40　mm　under　equal　stress　ratio　fatigue　loading　was　much　higher　than　that　of　the　specimens　with　bond　lengths　of　60　mm　and　80　mm.　It　was　found　that　the　fitting　method　had　better　stability　and　accuracy　in　fitting　the　bond-slip　curves　of　CFRP　sheet-Q690qD　high-strength　steel　specimens.　The　accuracy　of　the　fitting　maximum　bond　load　was　above　80　%,　which　can　provide　a　relevant　basis　for　the　subsequent　numerical　simulation　calculation.