The invention provides a multilevel-structured VS4 nano-powder, and a preparation method and an application thereof. According to the invention, a vanadium source solution and a sulfur source solution are mixed under stirring, wherein the molar ratio of vanadium to sulfur is controlled at 1:1-1:2, such that a mixed liquid is obtained; the mixed liquid is subjected to a hydrothermal reaction; when the reaction is finished, cooling, washing, collecting and drying are carried out, such that the multilevel-structured VS4 nano-powder is obtained. The process is simple and is easy to control. The prepared VS4 nano-powder has uniform chemical composition and relatively high purity. The nano-powder shows excellent electrochemical performance when used as a lithium/sodium ion battery electrode material. Also, the method overcomes a defect of high temperature of a traditional calcination method, and does not need large equipment and harsh reaction conditions. The raw materials are cheap and are easy to obtain; cost is low; yield is high; no post treatment is needed; and the method is environment-friendly. The method is suitable for large-scale production.