In this paper, we present a novel wearable flexible supercapacitor with the conductive carbon-nanotube (CNT)/fabric electrode and PVA/H3PO4 solid-state electrolyte, which is cost-effective and can be easily mass produced. Two kinds of fabric as the electrode substrates, cotton knitting fabric and polyester-fiber knitting fabric, are used for comparison respectively. The flexible fabric-based supercapacitors show good specific capacitance (11.51 mF/cm2 for cotton fabric-based supercapacitor (CFSC), 15.67 mF/cm2 for polyester-fiber fabric-cased supercapacitor (PFSC)) and high cycling stability (remaining more than 90% after 1000 cycles). This low cost and simple fabrication process makes this kind of supercapacitors feasible to be power supplies for wearable electronic devices.