Abstract: In order to develop ultra-high-strength prestressed steel strands with higher development intensity and superior comprehensive performance, using 87Mn wire rod as the raw material, the evolution of the microstructure and properties of the steel wire during the nine-pass drawing process were studied, revealing its strength-ductility mechanism. The results showed that the equiaxed pearlite structure was elongated and refined along the drawing direction with the drawing process, showing obvious directionality, and finally forming a typical fibrous drawing structure. The dislocation density inside the steel wire increases with the increase of drawing strain, and the growth rate is faster in the early drawing stage, from 2.35 × 10¹⁴ m^-2 to 4.59 × 10¹⁴ m^-2, and the growth rate of dislocation density gradually slows down in the middle and late drawing stages. After 9 passes of drawing, the tensile strength of 87Mn wire rod increases from 1 170 MPa to 2 085 MPa, and the elongation decreases from 12.56% to 7.20%. The change of mechanical properties during the drawing process is mainly divided into three stages:in the early stage of drawing, dislocation strengthening and boundary strengthening work together, and the strength contribution of dislocation strengthening growth is obvious, from 189 MPa to 460 MPa. At this stage, the strength of the steel wire increases with the increase of the drawing strain, and the plasticity decreases significantly. In the middle of drawing, dislocation strengthening and boundary strengthening work together. The strength contribution of boundary strengthening is significant, from 600 MPa to 806 MPa, and the growth rate of dislocation strengthening decreases. At this stage, the plastic decline trend of steel wire slows down and the strength continues to increase. In the late stage of drawing, a large number of cementite dissolved, and the strength contribution of solid solution strengthening was enhanced to 149 MPa. At this stage, the combined effects of boundary strengthening, dislocation strengthening and solid solution strengthening worked together. The strength growth rate of steel wire was obviously accelerated, and the plasticity decreased slightly.