<p>Thermoelectric fabrics can generate energy for wearable devices by utilizing the temperature difference between the human body and the environment. However, the performance of non-scarce materials is currently insufficient for large-scale applications. In this study, a high-conductivity MXene (Ti₃C₂T_<i>x</i>) was combined with cotton fabric via a dip-coating process, followed by in-situ polymerization to coat the surface with polypyrrole (PPy) and CuI nanocrystals. The introduction of MXene enhanced the fabric’s conductivity, while the electrostatic interaction and π-π conjugation between PPy and MXene modified the MXene layer defects and filled the gaps between layers, increasing the number of charge conduction paths and thus improving conductivity. The deposition of CuI nanocrystals further boosted the Seebeck coefficient. The resulting Cotton/MXene/PPy/CuI composite thermoelectric fabric achieved a conductivity of 12.6 S cm⁻¹, a Seebeck coefficient of 49.2&#xa0;μV&#xa0;K⁻¹, and a power factor of 3050 nW m⁻¹&#xa0;K⁻², while also exhibiting excellent flexibility and stability. A thermoelectric generator (f-TEG) with 22 pairs of TE fabrics generated 44&#xa0;mV at a ΔT of 30&#xa0;K, which was boosted to 3.67&#xa0;V, sufficient to power small electronic devices. This study provides new insights into energy supply solutions for portable thermoelectric generators and wearable devices.</p>