Flexible electrochromic devices (FECD) have been widely applied in smart displays, wearable devices, and other fields, however, the synchronous improvement of electrochromic performance and flexibility is still a challenge. In this paper, a fabric-based FECD with "side-by-side" structure is designed and constructed through inkjet printing. The polyaniline nanosheets with good dispersion are used as ink and electrochromic material, and the self-developed semi-solid electrolyte based on polyvinyl alcohol serves as gel electrolyte. Benefiting from the improved structure and excellent performance of individual components, the obtained FECD achieves a reflectivity change of 22.9%, and maintains the electrochromic ability after bending for 1000 times. This shows the potential in the field of wearable smart clothing and other flexible textile displays.