Crack　defect　is　a　common　failure　form　in　rotating　shaft.　The　breathing　effect　of　crack　defect　will　change　the　dynamic　characteristics　of　rotating　shaft　and　cause　multiple　frequency　components　in　the　radial　displacement.　A　novel　identification　method　using　visual　displacement-sensitive　fringe　pattern　(DSFP)　is　proposed　to　determine　the　existence　of　transverse　crack　in　rotating　shaft.　It　can　realize　the　efficient　measurement　of　vibration　signal　and　the　rapid　detection　of　the　shaft　crack　defect.　The　dynamic　equation　of　the　cracked　shaft　and　the　measurement　principle　for　the　shaft　radial　two　dimensional　vibration　using　single　camera　and　one　DSFP　are　illustrated　in　detail.　The　mathematical　relationship　between　the　dynamic　encoding　parameters　in　the　imaging　DSFP　and　the　real　shaft　radial　displacement　is　established.　The　measuring　results　obtained　both　from　the　proposed　system　and　the　traditional　two　eddy　current　sensors　based　system　verify　the　measurement　accuracy　of　the　proposed　system.　The　multiple　frequency　components　in　the　radial　displacement　of　cracked　shaft　at　different　speeds　are　analyzed.　When　the　rotation　speed　is　close　to　half　of　critical　rotation　speed,　the　double　frequency　component　is　obvious　and　its　amplitude　is　close　to　the　rotation　frequency　amplitude,　which　can　realize　the　effective　detection　of　crack　defect　in　rotating　shaft　system.　©　2022　Editorial　Office　of　Chinese　Journal　of　Mechanical　Engineering.　All　rights　reserved.