This study analyzed and explored the relationship between isthmic spondylolisthesis and disc degeneration by comparing the degree of disc degeneration in patients with isthmic spondylolisthesis, lumbar disc herniation, and asymptomatic healthy individuals. This study included a total of 138 cases, consisting of L5-S1 single segment lesion patients and a normal lumbar spine population. The cases were divided into three groups based on the type of disease: 58 cases in the isthmic spondylolisthesis group (IS), 50 cases in the lumbar disc herniation group (LDH), and 30 cases in the normal lumbar vertebrae group (NLV). The research findings indicate that the proportion of intervertebral disc degeneration in the LDH group is significantly higher than that in the IS group and NLV group (65.3% vs. 33.3% vs. 25.8%, P<0.05). The Pfirrmann grades of lumbar intervertebral discs (L1-L4) in the LDH group are significantly higher than those in the IS group and NLV group (P<0.05), and the intervertebral height index (IHI) (L1-L4) of lumbar vertebrae in the LDH group is significantly lower than that in the IS group and NLV group (P<0.05). The results showed that the degree of intervertebral disc degeneration in patients with isthmic spondylolisthesis was lighter than that in patients with lumbar disc herniation, and even similar to that in healthy individuals. The occurrence of isthmic spondylolisthesis may have slowed down the degeneration of non-affected segment intervertebral discs through certain factors.