Nanocomposite Nd2Fe14B/Fe3B magnetic materials with high performance have been obtained by crystallizing over-quenched ribbons. The effect of addition element of Cu and Zr on the phase component, microstructure and magnetic properties of Nd4.5Fe（76.5-x）B18.5Cu0.5Zrx (x= 0.4, 0.5, 1.5, 2.0, 3.0, 4.0) has been systematically investigated. The average grain size of Nd2Fe14B phase and Fe3B phase for the different compositions were calculated from X-day diffraction pattern, which are in accordance with TEM micrographs. For the Nd4.5Fe77B18.5 ribbons, the average grain size of Nd2Fe14B and Fe3B were 34.2 nm and 51.7 nm, and for the Nd4.5Fe76.3B18.5Cu0.5Zr0.4 ribbons, they were only 36.5 nm and 37.1 nm, respectively. It has been found that the additions of Cu and Zr cause the reduction of the difference of grain size between the hard magnetic phase and the soft magnetic phase, that increase the exchange coupling between them. Therefore, it would lead to the magnetic properties improvement. It has been determined that Nd4.5Fe76.3B18.5Cu0.5Zr0.4 was the optimal composition, and the optimal magnetic properties were: Br= 1.204 T, Hci= 271 kA/m, and (BH)max =111.2 kJ/m3.