Conductive polymers have attracted intense interest as electrode materials in supercapacitors, especiallythe flexible ones with graphene-based frameworks. To improve the electrochemical performance, a fourprongedapproach was developed here, by efficient fabricating poly(1,5-diaminoanthraquinone) graftedholey N-doped graphene (PDAA-HNrGO) via a solvothermal graft polymerization of 1,5-diaminoanthraquinone (DAA) onto holey N-doped graphene oxide (HNGO) following with reduction. Holey N-doped expandable graphene oxide (HNEGO) was oxidatively cut into smaller HNGO with morefunctional groups under the solvothermal condition, favoring the graft polymerization. Owing to theunique architecture, the proposed PDAA-HNrGO/rEGO electrodes possessed excellent electrochemicalproperty, especially the cycling stability. The flexible symmetric solid-state supercapacitors (SSSCs) possesseda capacitance of 320 mF cm2, power density of 275.6 mW cm2 and energy density of28.4 mWh cm2 at 0.50 mA cm2, with superior capacitance retention of 96% after 10,000 CV cycles.