In this paper,the relationship between the mechanical properties and the microstructure of a high-coercivity FeCrCo alloy was studied.Measurements on bending strength and fracture toughness showed that the mechanical properties of the high-coercivity FeCrCo alloy are much lower than the conventional FeCrCo alloy.TEM micrographs showed that the composition contrast between the two phases in the high-coercivity alloy is larger;XRD results indicated that the peak intensities of the high-coercivity alloy is lower and the half-peak-width is larger,which indicated that the spinodal decomposition processes are more successfully in the high-coercivity alloy.The enlargement of the composition contrast between α1 and α2 leads to the increase of crystal mismatch,the st rength of the alloy improved,but the ductility deteriorated,that is the reason why the mechanical properties of the high-coercivity alloy is poor.