【Abstract】 Objective To evaluate the biomechanical effects of percutaneous kyphoplasty. Methods 40 vertebral compression fracture specimens of 10 pigs were divided into study group and control group. The study group underwent balloon dilatation of vertebral plasty. The control group was treated with physiological saline gauze wrapped. The biomechanical properties were observed.Results There was no significant difference in the height of left and right vertebrae between the study group and the original vertebral body (P＞0.05). The height of left and right vertebrae of study group were significantly higher than that of the control group (P＜0.05). The vertebral rigidity of the study group was significantly higher than that of the control group (P＜0.05), and the maximum load was significantly lower than the control group (P＜0.05); The mean disc displacement was (2.11 ± 0.14) mm in the study group (3.21± 0.12) mm (t=4.026, P=0.006) at fixed loading of 500N.The strain value (1926 ± 46) με and the intervertebral disc stress (1.05 ± 0.08MPa) in the study group were significantly higher than those in the control group ((1800 ± 42) με, (0.90 ± 0.05) MPa, P＜0.05). Conclusion Percutaneous kyphoplasty can achieve good recovery of the maximum load and stiffness of vertebra and pain relief and prevent vertebral fractures again for vertebral compression fractures.