This study presents a novel approach to edit the dielectric genes of MXene to switch its electromagnetic (EM) functions. By annealing Ti3C2Tx nanosheets, MXene/TiO2 composites were prepared, and the effects of annealing on EM properties were investigated. The optimized composites at 300°C achieved a balance between EM energy loss and reflection, demonstrating excellent EM absorption and shielding performance. Based on the EM response characteristics of the composites, three customized devices were developed: an EM energy conversion device, a strain sensor, and an ultra-wideband (UWB) absorber. The UWB absorber showed good performance against oblique incidence and polarization, with S11 less than –10 dB from 1 to 20 GHz. The strain sensor was sensitive to structural deformation and could predict device safety. The energy conversion device enabled the recycling of waste EM energy. This work provides a novel strategy for developing multifunctional materials, with potential applications in EM protection, pollution management, and military camouflage. The study highlights the importance of dielectric gene regulation in enhancing device performance and response frequency, which is crucial for wireless communication components, sensors, and integrated electronic systems. The results demonstrate that the oxidation of MXene can be used to construct multi-dimensional metal oxides/MXene nanoarchitectures by adjusting the annealing temperature, offering a simple strategy for customizing interfaces and crystal defects. The study also shows that the unique EM response characteristics of Ti3C2Tx/TiO2 composites can be used to develop various EM devices, including energy converters, sensors, and absorbers. The findings suggest that the EM properties of MXene can be expanded through dielectric gene editing, opening new research directions for addressing EM challenges in the future.This study presents a novel approach to edit the dielectric genes of MXene to switch its electromagnetic (EM) functions. By annealing Ti3C2Tx nanosheets, MXene/TiO2 composites were prepared, and the effects of annealing on EM properties were investigated. The optimized composites at 300°C achieved a balance between EM energy loss and reflection, demonstrating excellent EM absorption and shielding performance. Based on the EM response characteristics of the composites, three customized devices were developed: an EM energy conversion device, a strain sensor, and an ultra-wideband (UWB) absorber. The UWB absorber showed good performance against oblique incidence and polarization, with S11 less than –10 dB from 1 to 20 GHz. The strain sensor was sensitive to structural deformation and could predict device safety. The energy conversion device enabled the recycling of waste EM energy. This work provides a novel strategy for developing multifunctional materials, with potential applications in EM protection, pollution management, and military camouflage. The study highlights the importance of dielectric gene regulation in enhancing device performance and response frequency, which is crucial for wireless communication components, sensors, and integrated electronic systems. The results demonstrate that the oxidation of MXene can be used to construct multi-dimensional metal oxides/MXene nanoarchitectures by adjusting the annealing temperature, offering a simple strategy for customizing interfaces and crystal defects. The study also shows that the unique EM response characteristics of Ti3C2Tx/TiO2 composites can be used to develop various EM devices, including energy converters, sensors, and absorbers. The findings suggest that the EM properties of MXene can be expanded through dielectric gene editing, opening new research directions for addressing EM challenges in the future.