Preparation of Nd(Fe,Mo)12NX/α-Fe nanocomposite magnets by the strip casting technique and subsequent mechanical alloying method are investigated. The result shows that the cooling rate of NdFe11Mo1 starting materials has great effects on the magnetic properties of the final Nd(Fe,Mo)12NX/α-Fe nanocomposite magnets, and the rapid solidification is helpful for improving magnetic properties. The nanocomposite magnets starting from strip have a Br of 65 emu/g, an iHc of 8372 Oe, and a (BH)max of 7.3 MG Oe, which is better than those of the corresponding materials starting from the conventional ingots. x-ray diffraction and scanning electron microscopy observations for the strips and the ingots show that not only the strip have much more 1:12 main phase and lower Fe-rich phase but also the distribution of 1:12 phase and Fe-rich phase in the strips are more uniform. The strips with the uniform microstructure are not only found to improve the efficiency of the high energy ball milling but also avoid the presence of excessive α-Fe nuclei. High resolution transmission electron microscopy observations show that the mechanically alloyed powders starting from the strips also have more homogeneous microstructure. In the end, the exchange coupling interactions are studied by the ratio of remanence coercivity Hr to the i- ntrinsic coercivity Hc (Hr/Hc). The Hr/Hc of the nanocomposite magnets is found to be 1.25, while that of single phase Nd(Fe,Mo)12NX material is about 1.0. This shows that there exists strong exchange spring effect between the hard phase Nd(Fe,Mo)12NX and soft phase α-Fe.