0bjective To find the best injection time and volume of PKP for preventing the leakage of bone cement in the treatment of osteoporotic burst fractures of thoracolumbar spine, by adjusting different infusion time and volume of bone cement during PKP surgery, parameters such as postoperative analgesic effect, vertebral height recovery degree and leakage rate were observed to evaluate the surgical effect. Methods Kyphoplasty was performed on 93 cases of thoracolumbar burst fracture with osteoporosis. During the operation, the infusion time and volume of bone cement were controlled, and the VAS, ODI, spinal canal occupation rate, Cobb Angle, leakage rate, vertebra height recovery ratio and complications were compared preoperatively, one week after surgery, six months after surgery and one year after surgery. Results The intraoperative leakage rate of bone cement was negatively correlated with the time of bone cement injection and positively correlated with the amount of bone cement injection. 80 of the 93 patients completed follow-up for one year. When the amount of cement injection was 2-3ml, the VAS score and ODI index were both higher than those of the other two groups one week after surgery. The change of the Cobb Angle was higher than that of the other two groups at 6 months and 1 year after surgery. The recovery percentage of the anterior vertebral height was lower than that of the other two groups at 6 months and 1 year after surgery. When the amount of bone cement injection was 6-7ml, the postoperative spinal canal occupancy rate was significantly higher than that before surgery. All the differences were statistically significant (P<0.05). Conclusion When using PKP to treat osteoporotic thoracolumbar fractures (type A3.2), satisfactory surgical results can be achieved when the infusion time of bone cement is 5-6min and the infusion volume is 4-5ml, and the treatment effect is accurate and safe.