Out-of-tolerance is inevitable during the construction of large pressure structures, and their correction and safety assessment have long been engineering challenges in the industry. This paper investigates corrective measures and evaluation methods for closure port out-of-tolerance in pressure structures. An indirect measurement method for corrective force was proposed based on the structural characteristics of the correction fixture, providing loading conditions for calculating structural internal stress caused by correction. A common model method for simulating correction internal stress of the local structural and the ultimate bearing capacity of the overall structure was established based on the flexible-rigid connection assumption of the closure port. Using this common model, the influence of local correction internal stress on the ultimate bearing capacity of the cabin segment structure was analyzed through simulating the correction of plate wall deviation exceeding tolerance of cabin segment structures. The research results show that the correcting internal stress caused by such plate wall deviation exceeding tolerance has minimal effect on the ultimate bearing capacity of the cabin segment structure and can generally be neglected. However, when the out-of-tolerance condition is more severe and the stress induced by correction approaches the material's yield strength, the out-of-tolerance correction will significantly impact the bearing capacity and may compromise the safe use of the pressure structure.
