This study focuses on preventing folding defects in the forging process of parachute harness parts. Through three- dimensional finite element analysis, it was determined that folding defects arise from uneven metal flow and timing differences in the filling of various regions. To address these issues, a preform die was designed and evaluated using multi-stage forging simulations. The results indicated that the preform die facilitated uniform metal flow, preventing folding defects and ensuring consistent filling across all key areas. To verify the simulation results, surface and cross-sectional metal flow analyses were conducted. Additionally, the preform die reduced the maximum die load, which is expected to extend die lifespan and improve overall process efficiency. These findings demonstrate that precise control of metal flow and the application of a preform die can significantly enhance the quality and durability of forged components, providing valuable insights for improving forging processes across various industries