Abstract: Materials that seamlessly integrate flexibility, multifunctionality, and electromagnetic interference (EMI) shielding capability have come to play an indispensable role in driving the advancement of 5G communication, wearable electronics, and artificial intelligence. Herein, the multilayered carbon nanotube (CNT)/polyvinyl alcohol (PVA) films with alternating structure are fabricated via layer-by-layer assembly, which endows them with exceptional flexibility and mechanical robustness. The CNT/PVA film with a CNT loading of 80 wt% exhibits an electrical conductivity of 500 S/cm and an EMI shielding effectiveness of 82 dB, while simultaneously maintaining a mechanical strength of 330 MPa. Notably, even after 1,000 repeated bending cycles, the tensile strength retains 96.2% of its original value, underscoring the excellent mechanical durability. Furthermore, CNT/PVA films demonstrate remarkable electrothermal and photothermal conversion capabilities. Upon application of a 2 V voltage, 80 wt% CNT/PVA films respond by rapidly reaching a stable surface temperature of 91oC within 25 s. When illuminated with simulated sunlight at an intensity of 120 mW/cm², 80 wt% CNT/PVA film exhibit a pronounced photothermal response, with its surface temperature stabilizing at 98oC. The flexible multifunctional film, by virtue of its integrated EMI shielding, electrothermal, and photothermal functionalities, holds great promise for advanced applications in 5G communication, artificial intelligence, and next-generation flexible wearable electronics.