In this work, an easy and green method was employed to successfully develop PdAu/graphene (RGO) nanocomposites, and PdAu/RGO/GCE was applied for the electrochemically detection of ascorbic acid (AA), dopamine (DA), uric acid (UA) and rutin. The electrochemical methods, such as cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were used to evaluate the electrochemical performances toward AA, UA, DA and rutin on the PdAu/RGO/GCE. Good linearships were observed for all the four molecules in the ranges of 12.5–700μM, 1.25–73.75μM, 2.5–66.25μM and 0.025–5.625μM, with the detection limits of 12.5μM, 0.75μM, 2.5μM and 0.025μM, respectively. Finally, the modified electrode has fairly good performance during the employment of real sample analysis to determine the content of AA, DA, UA and rutin. These results all indicate that the RGO modified bimetallic nanomaterials are supposed to be a promising material in the electrochemical determination of small biological molecules.