The invention belongs to a control and measuring method, and specifically relates to a circularity control and measuring process method of a large-diameter riveting segment. The method comprises the following steps: step one, calculating; steps two, performing structural optimization on a riveting assembly frame, i.e., additionally arranging a positioning compaction accessory on the platform of the riveting assembly frame so as to ensure that when a front end frame is assembled on the frame, the two frame segments at a butt joint separation surface are flush with each other, and the reviewing stress influences are reduced, the position of positioning compaction being a position obtained from step one through calculating; step three, arranging assembling positioning holes, i.e., respectively adding the assembling positioning holes at the quadrant gap of the front end fame and a butt joint position; step four, measuring; and step five, examining. The process method provided by the invention has the following remarkable advantages: the technology effectively controls circularity deformation of a first-order tail segment housing, and successfully controls the circularity to be within a scope of 3.5 mm of a general assembly use requirement. By digital measuring, through on-site testing verification and use of subsequently developed products, the measuring efficiency is enhanced by more than 30%, and the measuring errors are controlled to be within +/-0.05 mm.