Inferior contact interface and low charge transfer efficiency seriously restrict the performance of heterojunctions. Herein, chemically bonded α‐Fe2O3/Bi4MO8Cl (M=Nb, Ta) dot‐on‐plate Z‐scheme junctions with strong internal electric field are crafted by an in situ growth route. Experimental and theoretical results demonstrate that the internal electric field provides a powerful driving force for vectorial migration of photocharges between Bi4MO8Cl and α‐Fe2O3, and the interfacial Fe−O bond not only serves as an atomic‐level charge flow highway but also lowers the charge transfer energy barrier, thereby accelerating Z‐scheme charge transfer and realizing effective spatial charge separation. Impressively, α‐Fe2O3/Bi4MO8Cl manifests a significantly improved photocatalytic activity for selective oxidation of aromatic alcohols into aldehydes (Con. ≥92 %, Sel. ≥96 %), with a performance improvement of one to two orders of magnitude. This work presents atomic‐level insight into interfacial charge flow steering. Chemically bonded α‐Fe2O3/Bi4MO8Cl (M=Nb, Ta) dot‐on‐plate Z‐scheme junctions with strong internal electric field are crafted by an in situ growth route, which provides a powerful driving force, abundant atomic‐level charge flow highways and a decreased energy barrier for directional migration and spatial separation of photocharges, greatly improving the photocatalytic activity for selective photo‐oxidation of aromatic alcohols.