The invention discloses a preparation method of high-quality and large-scale novel two-dimensional material, namely, single-crystal less-layer antimonene. The liquid phase ultrasonic stripping technology is adopted, and a fifth main-group antimony nano-sheet is stripped through ultrasonic assisting of antimony powder, ethanol and surfactant. Firstly, the antimony powder and ethanol are mixed at room temperature; secondly, a proper amount of surfactant is added, the mixture is ultrasonically treated for a period of time under certain power, and then antimonene is massively prepared. Preparation process parameters are adjusted, and the size of antimonene can be adjusted. Reaction conditions are mild, the preparation process is simple, and the preparation method can be used for large-scale preparation. The less-layer antimonene prepared through the method is uniform in thickness and size, adjustable in size, high in purity and good in degree of crystallinity.