Plasmonic materials have drawn emerging interest with their high charge carrier density and solar harvesting ability, resulting in tunable enhanced absorption and scattering resonances. Herein, a novel plasmonic MoO3-x hybrid comprising orthorhombic MoO3-x nanorod and hexagonal MoO3 nanograin was obtained using a simple hydrothermal method. An excellent photochromic property with up to 40% solar modulation efficiency at 600-1000 nm was achieved, which was mainly attributed to the localized surface plasmon resonance (LSPR) absorption at around 900 nm and the polaron absorption at 650 nm with a synergistic effect. In comparison to the limited near-infrared absorption of conventional crystalline MoO3, a distinct modulation range in the critical range between visible and near-infrared was rationalized by a size effect deduced from Mie scattering theory. Our research provided a novel plasmonic molybdenum oxide hybrid to realize an optical modulation function with a tunable wavelength range for energy saving.