A transparent ultrahigh-molecular-weight polyethylene (UHMWPE)/MXene composite film with efficient UV absorption was developed for thermal management. The film was created by blending MXene with UHMWPE and vacuum pressing. The resulting film exhibited high photothermal conversion efficiency, reaching 65°C under 400 mW cm⁻² light irradiation, while maintaining 85% visible light transmittance and low haze (<12%). The film demonstrated significant cooling effects, reducing the temperature of a glasshouse model by 6–7°C compared to an uncovered model. Simulations using EnergyPlus software showed that the film could reduce annual refrigeration energy use by 31–61 MJ m⁻², with energy savings ranging from 3% to 12% in various climates. The film's UV-absorbing properties were attributed to the combination of MXene and BZT, which enhanced light absorption in the UV range (λ < 400 nm) while maintaining transparency. The film's mechanical properties were improved through the addition of MXene and BZT, with the 0.5M2B film showing the best balance of tensile strength, elongation, and modulus. The film also exhibited excellent thermal stability, with a thermal decomposition temperature (Td) of 453.10°C for the 0.5M2B film, significantly higher than that of pure UHMWPE. The film's anti-aging performance was tested under accelerated aging conditions, showing minimal degradation in visible light transmittance and UV shielding performance. The film's cooling energy-saving potential was evaluated in various climates, with the 0.5M2B film showing the highest energy savings, up to 61.3 MJ m⁻² in Phoenix, AZ. The film's potential for use in energy-efficient buildings and thermal management applications was highlighted, with the ability to reduce carbon emissions and energy consumption. The film's transparency and UV absorption capabilities make it suitable for applications such as windows, display screens, and thermal management systems. The study demonstrates the feasibility of scalable production and the potential for widespread use in energy-efficient and sustainable building applications.A transparent ultrahigh-molecular-weight polyethylene (UHMWPE)/MXene composite film with efficient UV absorption was developed for thermal management. The film was created by blending MXene with UHMWPE and vacuum pressing. The resulting film exhibited high photothermal conversion efficiency, reaching 65°C under 400 mW cm⁻² light irradiation, while maintaining 85% visible light transmittance and low haze (<12%). The film demonstrated significant cooling effects, reducing the temperature of a glasshouse model by 6–7°C compared to an uncovered model. Simulations using EnergyPlus software showed that the film could reduce annual refrigeration energy use by 31–61 MJ m⁻², with energy savings ranging from 3% to 12% in various climates. The film's UV-absorbing properties were attributed to the combination of MXene and BZT, which enhanced light absorption in the UV range (λ < 400 nm) while maintaining transparency. The film's mechanical properties were improved through the addition of MXene and BZT, with the 0.5M2B film showing the best balance of tensile strength, elongation, and modulus. The film also exhibited excellent thermal stability, with a thermal decomposition temperature (Td) of 453.10°C for the 0.5M2B film, significantly higher than that of pure UHMWPE. The film's anti-aging performance was tested under accelerated aging conditions, showing minimal degradation in visible light transmittance and UV shielding performance. The film's cooling energy-saving potential was evaluated in various climates, with the 0.5M2B film showing the highest energy savings, up to 61.3 MJ m⁻² in Phoenix, AZ. The film's potential for use in energy-efficient buildings and thermal management applications was highlighted, with the ability to reduce carbon emissions and energy consumption. The film's transparency and UV absorption capabilities make it suitable for applications such as windows, display screens, and thermal management systems. The study demonstrates the feasibility of scalable production and the potential for widespread use in energy-efficient and sustainable building applications.