Objective: To explore the kyphotic angle changes of thoracolumbar fractures after simple posterior short-segment internal fixation and the relationship between the intervertebral disc injury and the occurrence of kyphotic deformity. Methods: This study selected 134 patients with thoracolumbar fractures treated by orthopedic surgery in our hospital for retrospective analysis. Among them, 70 patients had intervertebral disc injury (the injury group) and 64 patients did not have intervertebral disc injury (the control group). The kyphotic Cobb angles of the two groups were compared before operation, 3 months after operation, 6 months after operation, 12 months after operation, and 6 months after removal of internal fixation. The incidence of recurrence of kyphosis between the two groups was compared and analyzed. Logistic regression analysis model was established according to whether the patients had kyphosis, and the relationship between disc injury and recurrence of kyphosis after operation was analyzed. Results: There was no significant difference in Cobb angle between the injury group and the control group before operation, 3 months after operation, 6 months after operation, and 12 months after operation (P>0.05); 6 months after the internal fixation removed, the Cobb angle of the injury group was greater than that of the control group (P<0.05); 6 months after the internal fixation taken out, the incidence of kyphosis in the injury group (24.29%) was higher than that in the control group 7.81%, and the difference was statistically significant (P<0.05); comparison of BMI, preoperative Cobb angle, regional angle (RA), anterior vertebra height (AVH), upper intervertebral angle (UIVA) between patients with recurring kyphosis and those without kyphosis, the difference was statistically significant (P<0.05); there was no statistically significant difference in age, gender, fractured vertebral body, and fracture AO classification between the two groups (P>0.05); logistic regression model results showed that increased BMI, preoperative Cobb angle, UIVA value increase and intervertebral disc injury were risk factors for recurrence of kyphosis after simple posterior short-segment internal fixation (P<0.05) and increased AVH value was a protective factor for the recurrence of kyphosis after simple posterior short-segment internal fixation (P<0.05). Conclusion: Intervertebral disc injury will increase the risk of kyphosis after a short-segment posterior fixation for thoracolumbar fractures.