Objective To summarize and analyze the characteristics and treatment strategies of post-traumatic lower limb deformity based on QIN Sihe Orthopaedic Surgery Database. Methods A clinical data of 837 patients with post-traumatic lower limb deformities treated by orthopaedic surgery between May 25, 1978 and December 31, 2020 in QIN Sihe Orthopaedic Surgery Database were analyzed retrospectively. The information of the patient’s gender, age at the time of surgery, region of origin, cause of trauma, deformity side, orthopedic surgery related information (operation time, location, type, and fixation method after operation) were summarized and analyzed. ResultsAll patients came from 32 provinces, municipalities, autonomous regions, and Taiwan in China. Among them, 551 cases (65.83%) were male and 286 cases (34.17%) were female. The age of the patients at the time of surgery was 3-84 years old, with an average of 27.6 years old, and the most patients were 16-45 years old (559 cases, 66.78%). The main cause of trauma was traffic accident injury (639 cases, 76.34%). The deformity mainly involved unilateral limbs, including 394 cases (47.07%) on the left side and 376 cases (44.92%) on the right side. The most patients were admitted between 2008 and 2017, accounting for 53.05% (444/837). All patients were operated on one or more sites (1 048 sites), among which ankle and toe surgery were the most, accounting for 48.38% (507/1 048). The patients received 1204 surgeries including tendon lengthening and soft tissue contracture release, et al. Orthopedic surgery combined with bone external fixation was used in 624 cases (467 cases of Ilizarov external fixation and 157 cases of combined external fixation), and plaster or brace external fixation was used in 213 cases. Conclusion Post-traumatic lower extremity deformity patients have a large proportion of males, with a wide geographical distribution, involving various parts of the lower extremities, and most commonly in the foot and ankle. Orthopedic surgery combined with bone external fixation (Ilizarov technique) is the main methods for correction and functional reconstruction of post-traumatic lower limb deformity.