To investigate the clinical efficacy of high tibial osteotomy (HTO) combined with 3D printing in the treatment of varus knee osteoarthritis (KOA). [Methods] Ninety-four patients with varus koa admitted to our hospital from January 2018 to June 2019 were enrolled in this study. According to the treatment methods, they were divided into two groups: bare-handed group (n=47) and 3D group (n=47), and were treated with HTO and HTO combined with 3D printing, respectively. The perioperative indexes of the two groups were compared. All the patients were followed up for 24 months. The time of full weight-bearing activity, knee extension and flexion range of motion (ROM), visual analog pain score (VAS), Western Ontario and McMaster University osteoarthritis index (WOMAC) and knee score (HSS) were compared between the two groups. The femoral tibial angle (FTA), medial proximal femoral angle (MPTA), posterior tibial slope (PTS) and Kellgren and Lawrence classification of medial and lateral compartments were compared between the two groups before and after treatment. [Results] The operation time of 3D group was longer than that of freehand group, and the times of fluoroscopy was less than that of freehand group (P＜0.05). With the extension of time, extension-flexion ROM and HHS score increased, VAS score and WOMAC index decreased in both groups (P＜0.05). and there was significant difference between the two groups (P＜0.05). FTA and PTS decreased and MPTA increased with time in both groups (P＜0.05), but there was no significant difference between the two groups (P＞0.05). There were no significant differences between the two groups in incision length, blood loss, walking time, incision healing time, hospital stay time, time for full weight-bearing activities and K-L classification of the internal and external compartment (P＞0.05). [Conclusion] HTO combined with 3D printing in the treatment of varus koa can reduce pain and accelerate the recovery of knee joint function, and the curative effect is exact.