This work grounds the relevance of the new ways for modifying the structure and properties of amorphous metallic alloys using severe plastic deformation (SPD) resulting the formation of nanocrystalline materials with new physical and mechanical properties. In this work, for the first time, the peculiarities of deformation nanocrystallization of one of the representatives of this class of material, such as NANOMET doped with phosphorus, namely, alloy Fe$_{81}$B$_{7}$Si$_{1}$P$_{10}$Cu$_{1}$ are studied. To perform SPD, the method of high-frequency mechanical-impact (HFMI) treatment is used in modes, which will ensure the maximum hardening effect as compared to the original rapidly solidified amorphous ribbon. The special features of the structure and kinetics of the deformation-induced crystallization of the alloy underwent the SPD by the HFMI method are studied. Two crystallization effects are established during heating of the amorphous ribbon of maximum hardness induced by the applied HFMI. First one, this is the shift of critical temperatures towards low exothermal temperatures, and second one, this is the lowering of the activation energy for crystallization as compared to the undeformed amorphous sample. The reasons of the observed SPD-induced changes in thermodynamic characteristics are established.