In order to improve the output efficiency and stability of friction nanogenerator (TENGs), acyl chloride-based multi-walled carbon nanotubes (CNT) and polyethyleneimine (PEI) were used to modify the fabric, which was mainly composed of polyester fiber. CNT and PEI were grafted onto the fabric surface. The experimental results showed that the amide bond was successfully formed on the surface of CNT/PEI modified fabric, and the surface roughness was significantly increased. When the concentration of CNT was 0.4 mg/mL, the prepared TENGs demonstrated the output voltage of 118 V and the output current of 12.5 μA, which also showed long-term stability.