Firstly, the multi-station cold upsetting extrusion forming method and product application of spherical pipe as the inner core of shock absorber were introduced, and then, the problem of inner folding defects encountered in the production of multi-station cold upsetting for spherical pipe was proposed. In order to analyze the reasons for the inner folding of the part, finite element simulation analysis and forming theoretical analysis were carried out on the initial forming process scheme, it was concluded that the non-uniform strength distribution of the material in the spherical part of upsetting extrusion was the main reason for the inner folding of the part. Furthermore, the material strength distribution curve of the spherical part for the actual upsetting extrusion  was obtained by cutting sampling and hardness measurement of the actual produced part and the hardness value was converted into strength value. The accuracy of the theoretical analysis was verified by the curve. Finally, based on the conclusion of the theoretical analysis, the forming process scheme was improved, and the parts were actually produced. The results show that the produced parts have no inner folding defects, so as to achieve the aim of ensuring the quality of parts and stabilizing the production.