The invention discloses a Ni-Cr-Fe coated structural metal porous material and a preparation method thereof. The invention discloses a Ni-Cr-Fe coated structural metal porous filtering material with high permeability and filtration accuracy. The preparation method of the Ni-Cr-Fe coated structural metal porous material comprises the following steps: firstly, carrying out uniform mechanical mixingon the Ni, Cr and Fe with certain granularities; then adding 3 to 5 percent of stearic acid, granulating, drying and carrying out mould pressing and cold forming; carrying out sectional vacuum pressureless sintering to obtain a Ni-Cr-Fe porous material supporting body; coating the surface of the supporting body with Ni, Cr and Fe powder with finer particle size, drying and carrying out vacuum sintering to obtain the Ni-Cr-Fe coated structural metal porous material. The method has the advantages of low energy consumption, almost no pollution and autonomous control of a pore structure and thickness of a film layer; in addition, the film layer and the porous supporting body of the Ni-Cr-Fe coated structural metal porous material are homogeneous materials, so that defects of inherent brittleness and unweldable property, short service life of a heterogeneous film layer of the ceramic coating structure porous material and the like are overcome; the Ni-Cr-Fe coated structural metal porous material can be applied to the field of industrial filtration with high filtration precision and filtration flux.