This study presents a novel photon–phonon-driven cascade catalysis method for the efficient conversion of methane to formaldehyde (HCHO). The process involves two stages: photocatalysis and phonon-driven decomposition. Specifically, a ZnO catalyst decorated with single Ru atoms (0.5Ru-ZnO) is used to selectively produce methyl hydroperoxide from methane and water under photocatalytic conditions. This intermediate is then thermally decomposed to form HCHO. The Ru atoms act as electron acceptors, enhancing charge separation and promoting oxygen reduction in photocatalysis. The optimal reaction conditions at 150 °C yield a high productivity of 401.5 μmol h$^{-1}$ (or 40,150 μmol g$^{-1}$ h$^{-1}$) and a selectivity of 90.4% for HCHO. This method offers a promising pathway for sustainable petrochemistry, providing an eco-friendly and efficient route to produce HCHO from methane, which is a crucial precursor in the production of industrial resins, plastics, and other chemicals.This study presents a novel photon–phonon-driven cascade catalysis method for the efficient conversion of methane to formaldehyde (HCHO). The process involves two stages: photocatalysis and phonon-driven decomposition. Specifically, a ZnO catalyst decorated with single Ru atoms (0.5Ru-ZnO) is used to selectively produce methyl hydroperoxide from methane and water under photocatalytic conditions. This intermediate is then thermally decomposed to form HCHO. The Ru atoms act as electron acceptors, enhancing charge separation and promoting oxygen reduction in photocatalysis. The optimal reaction conditions at 150 °C yield a high productivity of 401.5 μmol h$^{-1}$ (or 40,150 μmol g$^{-1}$ h$^{-1}$) and a selectivity of 90.4% for HCHO. This method offers a promising pathway for sustainable petrochemistry, providing an eco-friendly and efficient route to produce HCHO from methane, which is a crucial precursor in the production of industrial resins, plastics, and other chemicals.