Bisphenol A (BPA) is an effective endocrine-disrupting compound (EDC) that causes adverse effects on human health and environment. Therefore, it is indispensable to construct efficacious methods for evaluating the level of BPA to enhance the quality of life. In this study, a facile electrochemical sensor based on reduced graphene oxide-silver/poly-L-lysine nanocomposites (RGO-Ag/PLL) modified glassy carbon electrode (GCE) is proposed for the detection of BPA. The synthesized RGO-Ag/PLL nanocomposites displays high electrocatalytic activity towards the electrochemical oxidation of BPA. Differential pulse voltammetry (DPV) is used as an analytical method for the quantitative determination of BPA, and the fabricated electrochemical sensor exhibits a linear response to BPA in the range of 1-80 mu M with the limit of detection (LOD) of 0.54 mu M at a signal-to-noise ratio of 3. Additionally, the developed RGO-Ag/PLL/GCE sensor is applied to detect the BPA in drinking water, and obtains satisfactory results.