Objective To describe the characteristics of short arm deformity in patients with achondroplasia, and summarize the progress of its lenthening and reconstruction, so as to provide reference for clinical diagnosis and treatment. MethodsThe literature on the lenthening of upper limb with achondroplastic short arm deformity at home and abroad in recent years was reviewed, and the characteristics, extension methods, postoperative management, effectiveness evaluation, and related complications of short arm deformity were summarized. Results Achondroplastic short arm deformity affect the patient’s daily perineal hygiene activities. Although the upper limb is proportionately shortened, the humerus is mainly short limb deformity. Bilateral humeral lengthening is a common treatment method, and the traditional lengthening tools are mainly external fixation, guided by Ilizarov distraction osteogenesis concept; intramedullary lengthening is the latest treatment method. Lengthening percentage and healing index are commonly used for clinical evaluation indexes, and complications such as nerve injury may occur during upper limb lengthening. Conclusion In addition to appearance improvement, achondroplastic short arm lengthening is of great significance in achieving self-management of individual perineal hygiene. Lenthening and reconstruction methods are constantly being innovated and improved.