Particulate matter (PM) poses significant health risks, including respiratory and cardiovascular diseases, and has an extended atmospheric residence time as particle size decreases, leading to widespread environmental impacts. Filtration is widely employed across various fields as an economical and highly efficient method for capturing and reducing harmful airborne particles. The key performance indicators of a filter are its collection efficiency and pressure drop, where achieving high filtration efficiency with minimal pressure loss is desirable. However, as most filters are disposable, extending their service life is crucial. This necessitates increasing the dust holding capacity without inducing excessive pressure drop. In this study, a three-dimensional numerical simulation was conducted to evaluate how structural parameters, such as fiber diameter and fiber spacing, influence the dust holding capacity of nanofiber filters. The findings provide insights into optimizing nanofiber filter design to maximize air purification performance. This study is expected to contribute to industrial applications by offering a framework for enhancing filtration efficiency and prolonging filter lifespan.