The present invention discloses a method for complexing hydrothermal synthesis of uniform flower-like MoS2 nanospheres. The method comprises: sequentially dissolving a certain amount of a molybdenum source, a sulfur source and a complexing agent in deionized water to form a solution, regulating the molybdenum source concentration to 0.04-0.16 M, regulating a molar ratio of the sulfur source to the molybdenum source to 2:7-4:1, and regulating a molar ratio of the complexing agent to the molybdenum source to 2-6; placing the prepared solution in a closed hydrothermal reaction kettle, controlling the reaction temperature at 120-200 DEG C, and controlling the reaction time at 24-72 h; and after completing the reaction, cooling, carrying out suction filtration, washing, and drying to obtain the flower-like MoS2 nanospheres. According to the present invention, the synthesis method has advantages of mild condition, simple operation, uniform product morphology and particle size, good product dispersion property, and high yield; and the synthesized flower-like MoS2 nanospheres adopted as oil product hydrogenation catalysts, electrode materials, solid lubricants and the like have wide applications.