Abstract <p>Due to their excellent mechanical properties, cold-drawn pearlite steel wires are widely used in the field of engineering. As a key strengthening phase, the cementite phase has a significant impact on the mechanical properties of steel wires. However, the evolution mechanism of the cementite phase structure during the cold drawing process and the effects of these structural changes on the mechanical properties have not yet been clarified. To reveal the evolution mechanism of cementite structure and its influence on mechanical properties, this work employs a combination of high-resolution transmission electron microscopy (HRTEM) and molecular dynamics (MD) simulations to investigate, the relationship between cementite structure and deformation amount during the deformation process of pearlite steel wires, as well as the interaction laws of dislocations in ferrite with different structural cementite. The results indicate that during the cold drawing deformation of pearlite steel wires, strain accumulates at the ferrite-cementite interface, causing the cementite near the interface to first transition from a crystalline to an amorphous structure. As the amount of deformation increases, the region of amorphous structure gradually expands from the interface into the interior of the cementite. After the cementite structure undergoes an amorphous transformation, its hindering effect on dislocation slip in ferrite is stronger than that of crystalline cementite, which contributes to the increased strength of pearlite steel wires.</p> Graphical abstract <p></p>