Objective To evaluate the clinical effect of calcaneal cumulus reconstruction with subtalar joint preservation in the treatment of malunion of calcaneal fracture by clinical and imaging results. Methods From January 2016 to June 2018, 19 patients (19 feet) with malunion of calcaneal fracture were treated with subtalar joint-preserving calcaneal osteotomy and cumulus reconstruction. There were 15 males and 4 females, aged 20-45 years, with an average age of (32.5 + 5.1) years. All patients were unilateral fractures. Causes of injury: 12 cases of falling injury, 5 cases of traffic accident injury and 2 cases of other injuries. The time from injury to operation was 3-24 months, with an average of (12 +3.2) months. Results All patients were followed up for 12-38 months. According to Maryland''s ankle and foot function scoring criteria in the United States, 6 feet were excellent, 11 feet were good, 2 feet were fair and 0 feet were poor. The excellent and good rate was 89.4%. Postoperative Bohler''s angle, Gissane''s angle, calcaneal width (mm) and Maryland''s ankle function score before and after surgery were significantly different (P < 0.01). Conclusion The reconstruction of calcaneal cumulus with subtalar joint preservation is an effective method for the treatment of malunion of calcaneal fracture without subtalar articular cartilage injury.