The strong metal-support interaction (SMSI) plays a pivotal role in regulating electronic properties and activating surface oxygen species. In this work, we report light-irradiation-modulated SMSI for enhanced formaldehyde (HCHO) oxidation. Specifically, the SMSI between Pt nanoparticles (NPs) and Bi2MoO6 created surface-active oxygen at Pt-Bi2MoO6 interfaces to activate HCHO to dioxymethylene (DOM). Notably, light irradiation boosted the SMSI and catalytic activity. Moreover, photogenerated holes in Bi2MoO6 improved HCHO adsorption and activation, while photogenerated electrons migrated from Bi2MoO6 to Pt NPs to promote O2 adsorption and activation, accelerating the oxidation of DOM to CO2 and H2O. The light-modulated SMSI and the synergy between photocatalysis and thermocatalysis lead to enhanced catalytic oxidation activity, providing a practical strategy for indoor volatile organic compound (VOC) decomposition under ambient conditions.