Layered molybdenum disulfide/reduced graphene oxide (MoS2/RGO) nanocomposites were synthesized by solvothermal method, and were characterized by high-resolution transmission electron microscopy (HRTEM), field-emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), X-rayphotoelectron spectroscopy (XPS), and Raman spectroscopy. The electrochemical properties of the nanocomposites were studied by cyclic voltammetry and electrochemical impedance spectroscopy. Hydroquinone was selected as model molecular to investigate the electrochemical responses of the modified electrode. The results found that the synergetic effect of nanomaterials endowed the nanocomposite excellent electrocatalytic behavior towards the electrochemical reaction of hydroquinone. Under the optimal condition, hydroquinone can be sensitively detected in the range of 1–9 nM with the detection limit of 0.3 nM (S/N = 3). The obtained results revealed MoS2/GRO composites exhibited superior electrochemical performance in the detection of hydroquinone, and it may have promising potential for electrochemical sensors.