With the rapid development of flexible electronic devices, yarn supercapacitors (YSCs) as one kind of flexible energy storage devices are attracting more and more attention. Carbon nanotube (CNT) and conductive polymers (CPs) are widely investigated as potential active materials in energy storage field. Herein, an all-solid-state YSC was successfully fabricated via spinning CNT-coated cotton roving and in-situ polymerization of pyrrole. The proposed YSC demonstrated an areal specific capacitance of 421 mF cm −2 at a current density of 0.57 mA cm −2 as well as superior cycling performance. Moreover, the proposed YSC was comparatively flexible, confirming it as a promising power source candidate for portable and wearable electronics.