The interior stress of the widely used planar ring packing will attenuate along the axial direction when being pressed,so the packing rings near the gland have more contribution to seal.However,the pure graphite ring that plays the main sealing role in the flexible graphite packing is usually located in the middle of the packing group,and the sealing ability of the reinforced graphite rings at both ends is weak.To improve the sealing performance of flexible graphite packing,the structure of planar circular graphite packing group was optimized to change the stress distribution of the packing group by producing stress concentration,so the internal stress of the pure graphite rings is increase to improve the sealing performance of flexible graphite packing.The material parameters related to flexible graphite were determined,and the stress and seal performance of the packing group before and after optimization were analyzed with ANSYS and Fluent.The results show that after the plane ring packing group is optimized to V-shaped packing group,the interior stress of the pure graphite rings is improved,and the friction between the packing and the stem is decreased,which makes the packing sealing life longer.