Objective: To investigate the effect of posterior hemivertebra resection in different age groups on young children with simple hemivertebra deformity, and to conduct a single center follow-up study. Methods: The clinical data of 80 children with simple hemivertebra spinal deformity treated by posterior hemivertebrae from January 2013 to December 2020 were analyzed retrospectively, according to different age groups: 3~6 years old is the young group (n=43), 6-10 years old is the older group (n=37), all were treated with posterior hemivertebral resection. The clinical effects of the two groups were compared. Results: Compared with the older group, children in the young group had shorter operation time, less intraoperative blood loss and less fixed segments (P<0.05). There was no significant difference in the correction rate of kyphosis and scoliosis between the two groups of children immediately after the operation and the last follow-up, and the correction rate of C7PL-CSVL (P>0.05); compared with immediately after the operation, the kyphosis and side at the last follow-up The correction rate of convex Cobb angle is lower, and the correction rate of C7PL-CSVL is higher (P<0.05). There were no complications such as wound non-healing or poor healing, broken nails, and false joint formation in the two groups of children within 18 months after operation. One case of new kyphosis occurred in the young group, and non-fusion of bone graft in the older group. In 1 case, the fixed segment was extended and the deformity was corrected by the second operation. There was no significant difference in the complication rate between the groups (P>0.05). Conclusion: The effect of posterior hemivertebral resection for young children with simple hemivertebral deformity in the early stage is significant, which can shorten the operation time, reduce the amount of intraoperative blood loss and fix the segment, and improve the prognosis.