The poly(sodium 4-styrenesulfonate) functionalized spong graphene(3D-PSS-rGO) composites were fabricated via a green and simple method.The as made composites were characterized and analyzed by ultraviolet and visible absorption spectroscopy and scanning electron microscopy.An electrochemical sensor was constructed for the detection of daphnetin based on 3D-PSS-rGO composite film modified glassy carbon electrode(3D-PSS-rGO/GCE).Results showed that the 3D-PSS-rGO/GCE exhibited a strong enrichment effect and an excellent electrocatalytic activity towards daphnetin.Under the optimized conditions,good linear relationships were observed between oxidation peak current and daphnetin concentration in the ranges of 0.08-10.0 μmol/L and 10.0-60.0 μmol/L,with a detection limit of 0.04 μmol/L.The sensor was used in the determination of daphnetin content in girald daphne bark,with recoveries of 90.0%-96.0%.This study provides a reference for the determination of daphnetin in medicinal herbs.