<p>Stage open stoping with subsequent backfill mining method has been preferentially adopted for extracting thick, large-scale metal deposits. However, ore pillars in iron skarn deposits often exhibit time-dependent deformation due to the presence of clay minerals, resulting in a mismatch between pillar stability duration and backfill preparation time, compromising continuous extraction. To investigate the creep behavior of ore pillars, laboratory creep tests were conducted on iron ore samples. Based on the mineral composition determined by XRD analysis, a 3D DEM–FDM creep model of the ore pillars was constructed using BPB contact model to analyze the time-dependent deformation of ore pillars under non-uniform loading. By setting the width ratios of the stope to characteristics the pillar (<i>a/w</i>) at 0.5, 1.0, 1.5, and 2.0, the effect of stope width on pillar creep behavior was studied. The results show that iron ore exhibits a typical three-stage creep behavior, with long-term strength ranging between 70 and 80% of the UCS. The stress distribution in the pillar is characterized by lower stress in the middle and higher stress on the sides. As the <i>a/w</i> ratio increases, stress concentration at the pillar sides becomes significantly more pronounced. A stress distribution function was derived accordingly, and a critical threshold for allowable stope width was proposed. Under long-term loading, local failure initially occurs at the top and bottom of the pillar, followed by crack propagation inward, ultimately leading to overall instability. This failure process is more pronounced in pillars adjacent to wider stopes. The findings indicate that the DEM–FDM creep model based on the BPB contact model can effectively reproduce the time-dependent deformation behavior observed in engineering practice.</p>