The　capability　of　noble　metal　nanoparticles　(NPs)　as　efficient　charge　transfer　mediators　to　stimulate　Schottky-junction-triggered　charge　flow　in　multifarious　photocatalysis　has　garnered　enormous　attention　in　the　past　decade.　Nevertheless,　fine-tuning　and　controllable　fabrication　of　a　directional　charge　transport　channel　in　metal/semiconductor　heterostructures　via　suitable　interface　engineering　is　poorly　investigated.　Here,　we　report　the　progressive　fabrication　of　a　tailor-made　directional　charge　transfer　channel　in　Pt　nanoparticles　(NPs)-inlaid　WO3　(Pt-WO3)　nanocomposites　via　an　efficient　electrostatic　layer-by-layer　(LbL)　self-assembly　integrated　with　a　thermal　reduction　treatment,　by　which　oppositely　charged　metal　precursor　ions　and　polyelectrolyte　building　blocks　were　intimately　and　alternately　assembled　on　the　WO3　nanorods　(NRs)　by　substantial　electrostatic　interaction.　LbL　self-assembly　buildup　and　in　situ　self-etching-induced　structural　variation　of　WO3　NRs　to　a　microsized　superstructure　occur　simultaneously.　We　found　that　such　exquisitely　crafted　Pt-WO3　nanocomposites　exhibit　conspicuously　enhanced　and　versatile　photoactivities　for　nonselective　mineralizing　of　organic　dye　pollution　and　reduction　of　heavy　metal　ions　at　ambient　conditions　under　both　visible　and　simulated　sunlight　irradiation,　demonstrating　a　synergistic　effect.　This　is　attributed　to　the　imperative　contribution　of　Pt　NPs　as　electron　traps　to　accelerate　the　directional　high-efficiency　electron　transport　from　WO3　to　Pt　NPs,　surpassing　the　confinement　of　electron　transfer　kinetics　of　WO3　owing　to　low　conduction　level.　More　intriguingly,　photoredox　catalysis　can　also　be　triggered　simultaneously　in　the　same　reaction　system.　The　primary　in　situ　produced　active　species　in　the　photocatalytic　reactions　were　specifically　analyzed,　and　underlying　photocatalytic　mechanisms　were　determined.　Our　work　would　provide　a　universal　synthesis　strategy　for　constructing　various　metal-decorated　semiconductor　nanocomposites　for　widespread　photocatalytic　utilizations.