Objective To investigate the effect of minimally invasive limited osteotomy combined with Ilizarov external fixator on the ankle function and the walking motor function of the affected limb in patients with severe clubfoot. Methods A total of 56 cases patients withsevere clubfoot who were admitted to the Zhenjiang Medical District, General Hospital of Eastern Theater Command, PLA from January 2020 to October 2021 were selected as the research subjects and divided into two groups according to the random number table method. Patients in the control group (28 cases) were treated with Ilizarov external fixator, while patients in the experimental group (28 cases) were treated with minimally invasive limited osteotomy combined with Ilizarov external fixator, all patientsin of both groups were followed up for 6 months after operation. The scores of the International Club Foot Study Group (ICFSG) of patients before and 3 months after the operation, and the scores of the American Orthopaedic Foot and Ankle Surgeons (AOFAS) before and 1, 3, 6 months after the operation, the step speed, step length and 6-min walking distance before and 6 months after operation, as well as the postoperative complications occurrence during the 6 months after operation of patients were compared between the two groups. Results Compared with before operation, the ICFSG scores of morphological characteristics, functional status, X-ray photograph performance of patients in the two groups decreased significantly 3 months after the operation, and the experimental group was significantly lower than the control group; compared with before operation, the AOFAS scores of patients in the two groups increased significantly 1, 3, 6 months after operation, and the AOFAS scores of patients in the experimental group 1, 3, 6 months after operation were significantly higher than those of the control group; compared with before operation, the step speed of patients in the two groups accelerated significantly 6 months after operation, and the experimental group was significantly faster than the control group, the step length and 6-min walking distance prolonged significantly 6 months after operation, and the experimental group was significantly longer than the control group (all P<0.05); during the 6 months after operation, there was no significant difference in the total incidence of complications of patients between the two groups (P>0.05). Conclusion Minimally invasive limited osteotomy combined with Ilizarov external fixator in the treatment of patients with severe clubfoot, the treatment effect is good, which can prolong 6-min walking distance, improve the step speed, effectively enhance the ankle function and the walking movement function of the affected limb, and safety is good .