The invention discloses a two-dimensional metal carbide-based three-dimensional porous MXene network material and a preparation method thereof. The material is constructed by interconnection of two-dimensional metal carbide nanosheets (MXene) through chemical bonds or supermolecular force and has a three-dimensional porous structure. The preparation method comprises the following steps: treating acompact layered three-component metal carbide MAX-phase material with an etching agent to prepare an accordion-like two-dimensional MXene material; and then treating the accordion-like two-dimensional MXene material by using an alkaline solution with a certain concentration so as to obtain the three-dimensional porous MXene network material. The method provided by the invention is simple and feasible and can overcome the problem of severe agglomeration and stacking of the two-dimensional MXene material during preparation and application; and the prepared three-dimensional porous MXene networkmaterial has excellent physical and chemical properties and has significant application value in fields like electrochemical energy storage, catalysis and adsorption.