Smart and multifunctional textiles and fabrics are progressively developing, such that multifunctional fabrics are becoming more widespread. We elaborated herein multi-layered flax fabrics with superior flame retardancy and conductivity, which revealed fireproof feature while keeping conductivity during burning. The flax fabric was reinforced by layer-by-layer (LbL) deposition of sodium polyacrylate (SPA), polyethylenimine (PEI), ammonium polyphosphate (APP), and lastly a composite having poly(aniline-co-melamine) and montmorillonite (MMT) coated the aforementioned layers. The resulting multi-layered fabrics were characterized systematically by Fourier-transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDX) and thermogravimetric analysis (TGA). Flame retardancy of fabrics was conducted on pyrolysis-combustion flow calorimetry (PCFC), and a vertical burning test. TGA test showed a significant increase in the amount of residue of the treated fabrics (37%) against 19% assigned to untreated flax fabrics. Surprisingly, PCFC showed a very low peak of heat release rate (pHRR) of 15 W/g (HRR) for reinforced flax fabrics with respect to 234 W/g assigned to untreated flax fabrics (≈ −94%). In addition, the vertical burning test demonstrated the fireproof character of multi-layered fabrics. The conductivity of coated flax fabric was in the range of 1–8 × 10−7 S/cm before burning, which astonishingly survived up to 30 s after burning. This bi-functional flame retardant and conductive fabric enables taking next steps towards development of fireproof conductive materials for advanced technologies.