Molybdenum disulfide (MoS), a typical layered material, has important applications in various fields, such as optoelectronics, catalysis, electronic devices, sensors, and supercapacitors. Extensive research has been carried out on few-layered MoS in the field of electrochemistry due to its large specific surface area, abundant active sites and short electron transport path. However, the preparation of few-layered MoS is a significant challenge. This work presents a simple one-pot hydrothermal method for synthesizing few-layered MoS. Furthermore, it investigates the exfoliation effect of different amounts of sodium borohydride (NaBH) as a stripping agent on the layer number of MoS. Na ions, as alkali metal ions, can intercalate between layers to achieve the purpose of exfoliating MoS. Additionally, NaBH exhibits reducibility, which can effectively promote the formation of the metallic phase of MoS. Few-layered MoS, as an electrode for supercapacitor, possesses a wide potential window of 0.9 V, and a high specific capacitance of 150 F g at 1 A g. This work provides a facile method to prepare few-layered two-dimensional materials for high electrochemical performance.