Method for preparing gradient porous material

The invention discloses a method for preparing a gradient porous material, relates to a method for preparing a porous material, and solves the problem that the prior method for preparing the porous material has complex technique, high cost, hard control of foaming process, and hard control of aperture size and porosity factor. The method comprises the following steps: firstly, mixing matrix powder and pore-foaming agent, and then adding absolute ethyl alcohol into the mixture to prepare suspension; secondly, pouring the suspension into a mould, and then centrifugating and depositing the suspension; thirdly, after centrifugating and depositing the suspension, drying deposit, taking out rough blank after stripping, and putting the rough blank into a graphite mould to sinter to obtain blank; and fourthly, removing the pore-foaming agent in the blank to obtain the gradient porous material. The method has the advantages of simple preparation technique, low cost, gradually increased porosity factor along the radial direction from outside to inside, and easy control of the aperture size and the porosity factor.