Nanocrystalline materials commonly show properties superior to their bulk counterparts. Therefore, they are promising candidates used in the next generation of micro/nanodevices. In the present study, nanocrystalline CoNi alloys were fabricated using the pulsed electrodeposition method. The microstructures and components were examined by scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectrometer (EDX). Moreover, the magnetic properties of these alloys subjected to external stresses were studied using a magneto-mechanical coupling test system. The results obtained show that the nanocrystalline microstructure composed of ultrafine particles possessed good magnetic properties, and the saturation magnetization could reach approximately 2 T. In addition, the applied static and varying stresses did slightly affect the magnetic properties of the electrodeposits.