The invention relates to a novel three-dimensional elastic composite material and a preparation method thereof. The novel three-dimensional elastic composite material comprises following components: one layer of a composite ventilating film of polyfluortetraethylene and polyurethane, or a mesh polyurethane material or an elastic polyurethane film body (6), and at least one layer of a non-woven fabric (4) that is produced by the PE/PP bi-component spun-bonding process, the two components are synthesized in interval mode; the preparation method of the novel three-dimensional elastic composite material comprises following steps: (1) the non-woven fabric that is produced by the PE/PP bi-component spun-bonding process is fed, and the elastic body is stretched lengthways or transversely according to the proposition between 1 : 1.25 to1 : 8; (2) the non-woven fabric that is produced by the PE/PP bi-component spun-bonding process and the stretched elastic body are synthesized in the interval mode through hot rolling adhesion, chemical adhesion or ultrasonic adhesion; (3) the produced multilayer elastic composite material is slacked, and then coiled and shaped by a coiling device (11). The elastic composite material has good comfortable touch feeling and various appearances, and can be widely used in dresses, ornamental packages and medical and health materials, etc.