Abstract: To overcome the limitations of pristine MoO₃ gas-sensing materials, such as low sensitivity and sluggish response/recovery speed, this study aims to enhance its oxygen-sensing performance through conductive metal-organic framework modification. Zn-HHTP/MoO₃ nanocomposites with different Zn-HHTP loadings were synthesized via an in-situ deposition method. The crystal structure, morphology, and optical properties of the as-prepared samples were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and UV-vis-NIR spectroscopy, and the oxygen-sensing performance of the composites was systematically investigated. The results demonstrate that the 10% Zn-HHTP/MoO₃ composite exhibits a sensitivity of 3.29 toward 500 ppm oxygen at 125℃, which is 2.5 times higher than that of pristine MoO₃, with a response time shortened to 9.7 s. Moreover, this sample shows good linear response to different oxygen concentrations, high selectivity, and excellent stability, with only 6.1% attenuation in response value and less than 8.3% variation in baseline resistance after 28 days. Mechanism analysis reveals that the porous structure of Zn-HHTP provides abundant active sites for gas adsorption and reaction, thereby shortening the response time; meanwhile, the built-in electric field at the Zn-HHTP/MoO₃ heterojunction facilitates carrier separation and transport, enhancing the modulation of the interfacial depletion layer, which synergistically contributes to the significantly improved oxygen-sensing performance. This study provides a theoretical basis and experimental reference for the design and application of conductive MOF/metal oxide composite gas-sensing materials.