Abstract: The state of residual stress in the casing ring was regulated by bulging, and the influence of technological parameters on the bulging effect was explored. The residual stresses of several groups of TC4 rings were measured by blind hole method. The residual stress state was characterized by radar chart, standard deviation, mean value and range. The variation law of residual stress distribution of ring parts before and after bulging was obtained, and the influence law of different bulging amount on the regulation of residual stress of ring parts was summarized. ABAQUS finite element software was used to simulate the influence of different bulging quantities on the residual stress state of ring parts. The results show that the residual stress level of the ring decreases, the uniformity of residual stress distribution on each surface is improved, and the stress concentration phenomenon is alleviated. With the increase of bulging amount, the homogenization effect of residual stress becomes better. However, excessive bulging amount will also introduce residual stress.