The invention discloses a method for preparing antimonene through a lithium intercalation method. The method comprises the steps that firstly, a n-butyllithium hexane solution and antimony powder areput into a high-pressure reaction still for a hydrothermal reaction, so that on one hand, Li3Sb is formed, and on the other hand, Li ions are inserted into an interlayer; and then, an isopropyl alcohol aqueous solution is added, so that at the moment, two types of gas, namely SbH3 and H3, are generated, and interlayer Van der Waals force is destroyed to a certain extent; and finally, ultrasonic waves are adopted for aiding in sheet formation. The method is high in efficiency, yield and repeatability; the obtained antimonene is large in size; and large-scale preparation of the antimonene with asmall number of layers can be achieved.