Electrode materials with high electrochemical performance is of great importance for facilitating the practical large-scale application of advanced supercapacitors. In this paper, polyaniline@reduced graphene oxide (PANI@rGO) modified carbon cloth (CC) (ACC-PANI@rGO) was successfully prepared as the electrode for the construction of high-performance flexible solid-state supercapacitors (FSSC). The pristine carbon cloth was doubly activated by Hummers method and electrochemical treatment for the improvement of hydrophilicity and capacitance. Followed by the polymerization of aniline and adsorption and reduction of GO on the surface of treated CC, the flexible ACC-PANI@rGO electrode was obtained. It showed a maximum specific capacitance of 670 F g−1 at a current density of 0.5 A g−1. Further, the rGO layer was used as a protective layer to alleviate the expansion and contraction of PANI during the long-term process, thereby realizing the enhancement of cycling stability of ACC-PANI@rGO. The capacitance retention of ACC-PANI@rGO reached 87.5% of the initial specific capacitance after 6000 cycles at a high current density of 10 A g−1. The synergistic effect of the components enabled the FSSC assembled by two symmetrical ACC-PANI@rGO electrodes to achieve a high energy density of 111.96 µWh cm−2 at a power density of 0.5 mW cm−2 Moreover, it retained about 91.2% of the specific capacitance when repeatedly bent to 180° for 500 times, which is promising for the application of flexible energy storage devices.