In this study, a simple two-step strategy of self-assembly method is used to fabricate the graphene-based polyaniline composite hydrogel (PR-x) which attains a three-dimensional porous network structure. The microscopic morphology and structure composition are characterized and analyzed by SEM, XRD, FT-IR, Raman, XPS and other characterization methods. The results show that polyaniline (PANI) is uniformly distributed on the framework of three-dimensional porous graphene network, which can significantly inhibit the agglomeration of graphene. In addition, the electrochemical performance of graphene-based polyaniline composite hydrogel electrodes as supercapacitor is systematically studied. When the PANI content is high up to 75%, the specific capacitance is found to be as high as 762.8 F·g-1 at the current density of 1 A·g-1. Likewise, the specific capacitance retention rate is still as high as 77% when the scan rate increases from 5 mV·s-1 to 50 mV·s-1, meanwhile, the cycling stability is high up to 89.27% even after 3 000 cycles. The graphene-based polyaniline composite hydrogel electrode as a supercapacitor exhibits high specific capacity, excellent rate and cycling stability, providing the potential supercapacitor application.