The emergence of wearable electronic devices has dramatically changed people's daily life. However, the conductivity and wearability of most wearable fabric sensors still need to be improved. Therefore, it is of great importance that wearable, flexible electronic devices of fabrics be prepared with excellent antibacterial, electrochemical, and electrothermal properties. In this paper, a polypyrrole (PPy)/carbon nanotubes (CNTs) composite cotton fabric (CF) was prepared by in situ polymerization. The structure and morphology of the composite cotton fabric were characterized by Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy (Raman), and scanning electron microscope (SEM). The different process conditions were measured with a four-point conductive performance of the composite fabric, using the I−V curve, cycle volt−ampere characteristic curve, and curved sensitivity curve to investigate the electrochemical performance. In addition, its electrothermal performance and antibacterial properties were measured. When the concentration of pyrrole was 0.2 mol/L, the conductivity of PPy/CNT/CF reached 4.5 S/cm. Furthermore, the capacitance of the composite fabric as an electrode in the supercapacitor prototype could reach an order of 34.4 mF cm −2 . It was discovered that the composite fabric displayed a specific capacitive performance, good thermal conductivity, and antibacterial property.