<p>Fe-Mn-Si-Cr-Ni alloy, which exhibits a shape memory effect due to the reversible transformation between face-centered cubic (FCC) <i>γ</i>-austenite and hexagonal close-packed (HCP) <i>ε</i>-martensite, holds great application potential in various fields. Gaining a profound understanding of the martensitic transformation in this alloy is vital for optimizing its properties. In this study, a phase-field model was employed to simulate the martensitic transformation process. The simulation results reveal that as the ratio of the average density of gradient energy to the average density of elastic strain energy decreased, a plate-like martensite structure formed. The relationship between the martensitic volume fraction and the simulation time was found to be in good agreement with the Avrami equation. Moreover, it was observed that a significant interfacial stress was induced during the growth of martensite.</p>