Objective  To explore the range of normal female pelvic diameter lines in Tibetan nationality.    Methods  The subjects were Tibetan nationality female who underwent pelvic CT examination in the Radiology Department from January 2016 to December 2019 at the General Hospital of the Tibet Military Region of PLA. Ninty-six samples between the ages of 22 and 65 years, with an average age (46.06±11.42)years were recruited. Mimics 19.0 software was used to construct the digital three-dimensional model of pelvis, and to measure transverse diameter(TD), obstetric conjugate(OC), interspinous distance(ISD), sagittal midpelvic diameter(SMD), intertuberous distance(ITD), sagittal outlet diameter(SOD),diagonal conjugate diameter(DCD),sacrum length(SL), penal height(PH).Analysis of variance was used to compare different age groups, and Pearson correlation analysis was used to analyze the relationship between age and pelvic diameter.    Results  The linear measurement of TD was (132.08±6.15) mm, OC was (112.44±9.43) mm, ISD was (107.30±8.70), SMD was (129.06±7.73) mm, ITD was (123.02±12.08) mm, SOD was (118.80±8.87) mm, DCD was (127.49±9.80) mm, SL was (102.56±10.88) mm and PH was (36.57±4.57) mm.Cluster analysis showed that Lhasa Tibetans were closest to Uygurs.    Conclusion  The close clustering relationship between Tibetans and Uygurs in Lhasa suggests that there is a possibility of gene exchange between Tibetans and Uygurs in Hotan area in ancient times. The pelvic diameter of Tibetan women in Lhasa has changed significantly. Narrower OC, SL and PH make the pelvis flat, which is more and more detrimental to natural childbirth.