Inspired by the electrostatic interaction between the oppositely charged ions, here we report the fabrication of a series of MXene-filled polymeric films possessing superior EMI shielding performance, accompanied with excellent in-plane TC, as well as distinguished Joule heating performance that allows for fast deicing. Display omitted •Fabricating CS/MXene alternating layered films via LBL strategy.•Successful construction of continuous electrical/thermal conductive channel.•Absorption dominant (92%) EMI shielding with SSEt of 10, 650 dB cm2 g−1.•Excellent anisotropic thermal management capacity.•Distinguished Joule heating performance that allows for rapid deicing. Polymeric composites that feature both highly efficient EMI shielding and rapid heat dissipation have long been attractive, but it remains a significant challenge to fulfill such goals by virtue of lower film thickness and less filler. Inspired by the electrostatic interaction between oppositely charged chitosan (CS) solution and transition metal carbide (MXene) slurry, here we report a series of CS/MXene alternating layered films by taking advantage of layer by layer assembly strategy. The resultant 35-μm thick CS/MXene multilayer film presents a maximum EMI SE of 40.8 dB, a high specific EMI SE (SSEt) of 10, 650 dB cm2 g−1, together with superior thermal conductivity (6.3 W m−1 K−1) and excellent Joule heating capacity. Thus, this research opens up a new horizon for achieving satisfying EMI shielding and heat dissipation capacity, which will further benefit the development of MXene‑based composite materials in next-generation electrical devices.