<p>Efficient and high-precision magnetic particle grinding technology has become a bottleneck technology for the manufacturing and repair of high-performance aircraft engines. The project aimed to address the issue of low precision and efficiency in magnetic particle grinding, and to study the principle of precision magnetic particle grinding on the inner surface of aircraft engine bent pipes. Based on the discrete element optimization theory of slotted magnetic pole structure, a discretized finite element model is established. By the slotted discrete finite element simulation of magnetic pole structure, the optimized magnetic pole increased the magnetic induction intensity and improves the grinding efficiency by 16–24% compared to before optimization.The research results have improved the precision and efficiency of magnetic particle grinding on the inner surface of aircraft engine bend pipes, laying a theoretical foundation for obtaining a fully optimized precision magnetic particle grinding process. It is of great significance for improving the quality of the inner surface of aircraft engine bend pipes and enhancing the performance of aircraft engines.</p>