The invention provides a preparation method and application of a short nano-rod self-assembled vanadium tetrasulfide micro-sphere. The preparation method comprises the following steps: respectively placing vanadium source substance and sulfur source substance in mol ratio of 1: 10-1: 15 in two porcelain boats, placing two porcelain boats in a tubular atmosphere furnace, exhausting air so that the tubular atmosphere furnace is in a state of -1 to 0 MPa; warming the atmosphere furnace to 300-1000 DEG C in a warming speed of 5-10 DEG C/min, keeping temperature for 0.5-5, and then performing calcination; cooling a calcined sample under the condition of continuously piping the inert gas, cleanly washing, collecting and drying to obtain the short nano-rod self-assembled vanadium tetrasulfide micro-sphere. The method is simple and easily controlled in process, the prepared vanadium tetrasulfide nanometer powder is uniform in chemical constitutions, high in purity, and provided with a specific short nano-rod self-assembled structure, and has excellent performance while being used as ferromagnetic material and lithium/sodium ion battery electrode material. Furthermore, the raw material is cheap and easy to obtain, the method is low in cost, high in yield, free from after-treatment, friendly to environment, and suitable for large-scale production.