Objective：To explore the application value of coronal T2-weighted Dixon imaging based on magnetic resonance imaging in the classification of interspinous ligament degeneration in patients with low back pain. Methods：Imaging and clinical data of 60 patients with low back pain who underwent lumbar magnetic resonance imaging（MRI）examination from January 2022 to August 2023 were prospectively collected. According to the fat and water images of coronal T2-weighted Dixon sequence，the research group classified the entire interspinous ligament into type A，B，C，D and mixed type. The mixed type included four subtypes：B-C，D-B，D-B- C，and D-C. In the control group，the middle part of the interspinous ligament was classified into type A，B，C，and D by sagittal T1WI/ T2WI sequence. Differences of degeneration types of interspinous ligament between the two groups were compared. Results：The consistency of results between the two classification methods was as follows：for the research group，the Kappa coefficient within observers ranged from 0.852 to 0.916，and between observers ranged from 0.747 to 0.753；for the control group，the Kappa coefficient within observers ranged from 0.801 to 0.823，and between observers ranged from 0.689 to 0.703. The classification results of 122 interspinous ligaments were statistically different between the two groups（P < 0.05）. The incidence of type C in the research group was 54.1%，significantly higher than 9% in the control group. The newly added mixed type had an incidence of 46.7% in the research group，with B-C type and D-C type being more common. Conclusion：The classification method of interspinous ligament degeneration based on coronal T2-weighted Dixon magnetic resonance imaging is reliable and reproducible，which can improve the identification rate of interspinous ligament and the detection rate of type C，and can further distinguish the mixed types and its subtypes.