The invention discloses a two-dimensional transition metal boride material, a preparation method and application thereof. The molecular formula of the two-dimensional transition metal boride material is represented as MB or M n B 2n‑2 , M is selected from pre-transition metals Mn, W, or a combination of any two or more of Mn, W and Cr, Fe, Mo, B is boron element, and n is 2, 3 or 4. The two-dimensional transition metal boride has a tetragonal crystal structure, and the space group is Cmmm. The present invention also provides a method for preparing the aforementioned two-dimensional transition metal boride material by etching the MAB phase in a dilute alkaline solution. The layered material of the two-dimensional transition metal boride material provided by the present invention has a series of advantages such as adjustable magnetic properties, thermal conductivity, electrical conductivity, multiple active sites, etc. Its structure and properties are regulated by regulating the content, position and type of M-site elements Moreover, the preparation process is simple and easy to operate, and has potential application prospects in the fields of wave absorption, energy storage, catalysis and the like.