A catalyst-free photoinduced deconstructive fluorosulfonylation cascade of spiro dihydroquinazolinones with DABSO and NFSI is reported. This protocol features mild reaction conditions, good yields and excellent functional group tolerance, providing a practical approach to the quinazolin-4(1H)-one-functionalized aliphatic sulfonyl fluorides. In addition, the ease of gram-scale synthesis and the versatility of the SuFEx exchange highlight the application potential of this protocol.