The chemodivergent synthesis of carbonyl-containing polycyclic quinazolinones have been reported, which features green reaction conditions, good functional group compatibility, compatible of 1°, 2° and 3° alkyl free radical precursors and applicable to gram-scale synthesis. Mechanistic experiments indicate a radical cascade cross-coupling/cyclization process is involved. It is an efficient example describing the direct activation of inactive α‐halocarbonyls to synthesize 2,3-fused polycyclic quinazolinone skeletons, which possess a wide range of biological activities.