With the rapidly increasing development of portable devices and flexible electronic devices, multifunctional composites with excellent mechanical strength, great electromagnetic interference shielding, great Joule heating performance and strong fire-resistant protective performance are noticeably required. Herein, inspired by the sandwich structure, we have designed a montmorillonite/aramid nanofibers@MXene (MMT/ANFs@MXene) nanocomposite with an alternating multilayered structure via a simple AVF process. In this nanocomposite, the ANFs/MMT (AT) layer acts as a mechanically reinforced and insulation protection layer, while the MXene layer maintains a complete conductive network. The superior alternating multilayered structure endows the nanocomposite with outstanding mechanical properties (154.66 MPa, 14.22%) and excellent EMI shielding effectiveness values (58.4 dB). In addition, the fire-resistant protective performance of the nanocomposite improves its safety and reliability, especially, the EMI shielding effectiveness is maintained at ∼34 dB after burning for 30 s. Besides, the MMT/ANFs@MXene nanocomposite shows excellent Joule heating performance with a fast thermal response, low driving voltage and long-time temperature stability, which could reach 110.2 °C at only 3 V applied voltage within 10 s. As a result, this work presents a novel strategy for constructing multifunctional composites with outstanding overall performance, which will broaden application areas and prospects in thermal management and EMI shielding in wearable products.