to analyze the relationship between sagittal imaging parameters of spine and pelvis in patients with degenerative lumbar spinal stenosis (single segment, double segment, multi segment (three or more segments) and normal volunteers, and to explore the significance of sagittal morphology of spine and pelvis in the pathogenesis of degenerative lumbar spinal stenosis and its guiding role in the formulation of surgical plan. Methods: 192 patients with degenerative lumbar spinal stenosis with complete imaging data and clear clinical manifestations were selected from November 2019 to November 2021, including 72 patients with single segment degenerative lumbar spinal stenosis, 63 patients with double segment degenerative lumbar spinal stenosis, 57 patients with multiple segments (three or more segments) degenerative lumbar spinal stenosis, and 64 healthy volunteers, The basic clinical data (including gender, age, BMI) and course of disease of the subjects were recorded, and the sagittal imaging parameters (including LL, TLK, TK, SVA, PI, PT, SS) of the spine pelvis were measured. The measurement data and statistical data in the above data were statistically analyzed by ANOVA and X2 test. Results: the course of disease in single segment group was significantly less than that in double segment group and multi segment group (P < 0.05), and the course of disease in double segment group was also significantly less than that in multi segment group (P < 0.05); SVA of single segment group was significantly larger than that of double segment group and multi segment group (P < 0.05), LL, TK and SS of multi segment group were significantly smaller than that of single segment group and double segment group (P < 0.05), PT of multi segment group was significantly larger than that of single segment group and double segment group; LL, TK and SS of single segment group, double segment group and multi segment group were significantly lower than that of normal group (P < 0.05), PT of single segment group, double segment group and multi segment group were significantly higher than that of normal group (P < 0.05), SVA and PI of single segment group were significantly higher than that of normal group (P < 0.05). Conclusion: compared with healthy volunteers, patients with degenerative lumbar spinal stenosis showed that the sagittal curvature of the spine and pelvis disappeared, the pelvis tilted back, and the sacral platform tended to be in a high energy consumption state of levelization, However, the patients with single segment degenerative lumbar spinal stenosis have obvious sagittal imbalance due to the short course of disease and incomplete compensatory changes.