Femtosecond　laser　fabrication　outperforms　the　traditional　fabrication　techniques　with　high　precision,　high　efficiency,　low　collateral　damage　and　wide　applicability,　which　has　shown　to　be　a　powerful　tool　in　precision　machining.　Imaging　the　ultrafast　dynamics　of　femtosecond　laser　fabrication　is　necessary　for　understanding　the　processing　mechanism　and　for　establishing　the　corresponding　physical　models.　Up　to　now,　ultrafast　measurement　techniques　based　on　the　pump-probe　strategy　are　the　most　used　methods.　However,　they　are　limited　by　laser　energy　stability　and　materials　surface　uniformity,　which　have　a　heavy　impact　on　the　dynamic　measurement　precision　of　femtosecond　laser　fabrication.　To　overcome　this　limitation　of　the　traditional　pump-probe　techniques,　we　developed　chirped　spectral　mapping　ultrafast　photography　(CSMUP),　which　can　achieve　single-shot　real-time　ultrafast　imaging　with　a　frame　rate　of　about　250　billion　frames　per　second　(temporal　frame　interval　of　4　ps)　and　a　spatial　resolution　of　less　than　833　nm.　We　experimentally　imaged　the　dynamics　of　femtosecond　laser　ablation　in　silicon　under　a　400　nm　femtosecond　laser　exposure　with　CSMUP,　and　the　experimental　result　agreed　well　with　previous　theoretical　models.　CSMUP　provides　a　new　strategy　to　improve　the　efficiency　and　accuracy　of　femtosecond　laser　fabrication　by　a　single-shot　dynamic　measurement　of　the　interaction　between　the　femtosecond　laser　and　materials,　and　it　is　expected　to　work　as　a　real-time　detection　method　for　various　ultrafast　phenomena.　©