A ternary coupling material of phosphomolybdic acid cluster bridging carbon dots and polyaniline (CDs-PMo12-PANI) nanofibers is designed to improve electrochemical performance of PANI. The proton-rich PMo12 bonds with PANI via electrostatic interaction to promote the proton-doping level of PANI. The reversible multi-electron redox reactivity of PMo12 contributes to improving pseudo-capacitance of PANI. PMo12 cluster bonds with carbon dots via chemisorption interaction to achieve the immobilization of hydrosoluble PMo12. PMo12 cluster keeps a bridge connection between polyaniline chain and carbon dots. The good electric conductivity of carbon dots and the distinct bonding interface of CDs-PMo12-PANI contribute to improving rate capability and cycling stability of PANI. CDs-PMo12-PANI achieves high specific capacitance of 479 Fg(-1) at 1 Ag-1, reasonable rate capacitance retention of 69.3% when increasing current density from 0.5 to 10Ag(-1) and reasonable cycling capacitance retention of 68.1% after 1000 cycles at 5Ag(-1). CDs-PMo12-PANI shows higher electrochemical performance of capacitance, rate capability and cycling stability than PANI, PMo12-PANI and CDs-PANI. All-solid-state flexible supercapacitor based on CDs-PMo12-PANI electrode exhibits high specific capacitance of 118.6Fg(-1) and specific energy of 37.1Whkg(-1) at 1Ag(-1). A single unit of high-performance supercapacitor can directly drive various electronic devices, indicating effective electrochemical energy storage of CDs-PMo12-PANI.