Abstract: Taking a J-shaped ring forging of IN718 alloy as the research object, this paper studies the defects and mechanical properties of the forging after it is prepared and formed through the forging process. In this paper, by optimizing the material distribution of the J-shaped forging during the forging process, the Deform software is used to simulate the forming process of the forging, and the Forging software is applied to simulate the distribution of its grain flow lines. On this basis, the defects in the forging process are identified, analyzed and summarized, so as to re-optimize and develop a complete process flow. The results show that compared with the traditional forming process, the near-net shaping process can more effectively reduce material loss and improve material utilization. Through the cause analysis of the forming defects of the forging in the early stage, combined with simulation and actual forging, a forging process that meets the requirements for the forging's shape, size and performance is designed, and products with good size and shape are obtained. In addition, the performance of the forging is evaluated by analyzing its grain size. The grain size of the forged part reaches Grade 8-10, which far meets the Grade 4 grain size requirement specified in the standard. This study provides strong data support for the subsequent forging forming design of similar superalloy profiled forgings, and offers certain experience for the optimization and innovation of the production process of this type of forgings. Keywords: IN718; J-shaped ring; defects; forging; performance