This article presents a dual-selective radiative cooling design based on a scalable polymer-metal thermal emitter, which exhibits selective emission in both atmospheric transparent windows (8–13 μm and 16–25 μm) and reflection in the remaining mid-infrared and solar wavebands. The dual-selective thermal emitter demonstrates an ultrahigh subambient cooling capacity of -9 °C under strong sunlight, surpassing existing typical thermal emitters and commercial counterparts. It also shows high weather resistance and color compatibility, making it highly practical for sustainable thermal management. The design is based on molecular vibration theory and Mie scattering theory, using polyformaldehyde (POM) and polytetrafluoroethylene (PTFE) polymers with specific molecular vibrations and hierarchical nano-micron structures. Field tests in an arid environment confirm its superior cooling performance, and it outperforms conventional roofing materials in real-world applications. The colored dual-selective emitters maintain subambient cooling even with reduced solar reflectance, demonstrating high color compatibility. This work provides a scalable and practical solution for efficient radiative cooling.This article presents a dual-selective radiative cooling design based on a scalable polymer-metal thermal emitter, which exhibits selective emission in both atmospheric transparent windows (8–13 μm and 16–25 μm) and reflection in the remaining mid-infrared and solar wavebands. The dual-selective thermal emitter demonstrates an ultrahigh subambient cooling capacity of -9 °C under strong sunlight, surpassing existing typical thermal emitters and commercial counterparts. It also shows high weather resistance and color compatibility, making it highly practical for sustainable thermal management. The design is based on molecular vibration theory and Mie scattering theory, using polyformaldehyde (POM) and polytetrafluoroethylene (PTFE) polymers with specific molecular vibrations and hierarchical nano-micron structures. Field tests in an arid environment confirm its superior cooling performance, and it outperforms conventional roofing materials in real-world applications. The colored dual-selective emitters maintain subambient cooling even with reduced solar reflectance, demonstrating high color compatibility. This work provides a scalable and practical solution for efficient radiative cooling.