Polyetherimide (PEI) and polyarylethernitrile (PEN) are high–performance materials for various applications. By optimizing their fiber morphology, their performance can be further enhanced, leading to an expanded range of applications in carbon fiber composites. However, developing processes for stable and efficient fiber production remains challenging. This research aims to simulate the preparation of high–performance ultrafine PEI or PEN fibers using electrospinning. A mesoscopic simulation model for centrifugal melt electrospinning was constructed to compare and analyze the changes in molecular chain orientation, unfolding, fiber diameter, and fiber yield under high-voltage electrostatic fields. The simulation results showed that temperature and electric field force had a particular impact on the diameter and yield of PEI and PEN fibers. Changes in rotational speed had negligible effects on both PEI and PEN fibers. Additionally, due to their different molecular structures, PEI and PEN, which have different chain lengths, exhibit varied spinning trends. This study established a mesoscopic dynamic foundation for producing high-performance ultrafine fibers and provided theoretical guidance for future electrospinning experiments.