Inherent to the influence of multiple factors, including environmental conditions and service time, pre stressed steel strands corrode over time.This leads to concrete rust expansion and crackingand poses a critical threat to structural durability. To monitor the extent of cracking in this context, this study proposes a finite element simu lation method based on piezoelectric wave propagation. Using Abaqus, a micro-scale model comprising mortar, ag gregate, structural rebars, prestressed steel strands, and piezoelectric ceramics was constructed. By analyzing the e lectromechanical coupling process, concrete crack development induced by steel strand rust expansion was compre hensively monitored. The findings demonstrated that as corrosion progressed from the onset to mild stages, the pie zoelectric signal-peak voltage increased by 13.4%, while the first wave reception time decreased by 1.2%. From the mild to accelerated corrosion stages, and up to the theoretical corrosion rate stage, influenced by corrosion-in duced cracks, the peak voltage decreased, and the first wave reception time extended. Specifically, the voltage de creased by 6.6% and 48.6%, and first wave reception time increased by 6.0% and 29.8%, respectively. Based on the results of validation experiments, with discrepancies of less than 0.32 mV, the reliability of the proposed piezoe lectric wave propagation method for monitoring prestressed concrete rust expansion using finite element models was confirmed.