OBJECTIVE: To explore the soft tissue balancing method for artificial knee arthroplasty in knee flexion contracture deformity. Methods: A targeted soft tissue balancing procedure was developed and applied to 33 clinical cases of artificial knee arthroplasty with knee flexion contracture greater than 20 degrees (20-60°), and a retrospective study was conducted to analyze the degree of preoperative deformity, intraoperative soft tissue release, postoperative deformity correction and functional changes of the knee. Results: In 20 of 33 patients (60.6%), the flexion deformity of the knee could be basically corrected intraoperatively by soft tissue release alone, and less than 40% of the patients required two intraoperative distal femoral osteotomies for correction, and all were patients with flexion contractures greater than 30 degrees. In patients with flexion contracture greater than 40 degrees, in addition to the release of the lateral collateral ligament on the tense side, both the internal and external posterior capsules had to be released: for flexion contracture less than 40 degrees, the more severe the internal and external varus deformity, the lower the chance that both posterior capsules had to be released at the same time. The clinical results showed that all 31 patients were able to achieve full knee extension intraoperatively, except for 2 cases in which 5° and 8° of knee flexion remained. After 31.3 months (6-66 months) of follow-up, the knee score (HSS score) increased from a mean of 28.8 preoperatively to a mean of 79.2, and the mean knee flexion contracture was 1.30° (-3 to 10°). The knee range of motion (ROM) increased from a mean of 57.69 to 97.69 degrees preoperatively. Conclusion: Soft tissue release is the main tool to correct severe flexion contracture of the knee joint, and intraoperative soft tissue release varies in different degrees of knee deformity and different diseases. A good and reasonable soft tissue balance can still result in significant functional recovery and deformity correction of the highly flexed contracted knee after artificial knee arthroplasty.