Objective To measure the sagittal anatomical parameters of the spine and pelvis based on EOS imaging system, and to evaluate the stress of the lower lumbar spine by finite element analysis (FEA). Methods A total of 44 subjects examined by EOS imaging system were included, including 11 sacral lumbar vertebra patients and 33 normal subjects. The sagittal plane parameters of lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt (PT) and sacral slope (SS) were measured and compared in both groups. Pearson test was used to analyze the correlation between PI and LL in the two groups. At the same time, the finite element model of the lower lumbar vertebra was established. The stress condition of the lumbar spine model during forward bending, backward extension and left and right bending was evaluated by FEA method. Results The differences of PI, PT, SS and LL between the two groups were statistically significant (P<0.05). The correlation study found that there was a positive correlation between the two groups of subjects' PI and LL, including the lumbarization group (r = 0.69, P<0.05) and the normal group (r = 0.52, P<0.05). Under the conditions of forward bending, backward stretching, left bending and right bending, the bending moment of the model was 2 Nmm, and the stress concentration gradually decreased from bottom to top. The maximum stress concentration point was located at the lower articular process. Conclusion The physiological curvature and stress distribution of the lumbar spine in lumbarization population were different than normal, especially the stress concentration of the transitional intervertebral disc and articular process joint was obvious, and early degeneration of the spine was easy to occur.