[Objective] To study the early clinical effect of calcaneus internal transfer osteotomy and fusion of taloclavicular joint in the treatment of secondary flatfoot with taloclavicular arthritis. [Methods] The clinical data of 53 patients with secondary flatfoot and taloclavicular arthritis were analyzed retrospectively from may 2012 to may 2018. They were randomly divided into operation group and conservative group. 33 patients in operation group were treated with taloclavicular joint fusion combined with calcaneus osteotomy, and 20 patients in conservative group were treated conservatively with insoles. The VAS score, AOFAS ankle and hind foot score and imaging indexes of the two groups were compared. [Results] All patients were followed up for an average of (15.7 ± 3.9) months. There were significant differences in VAS score, AOFAS score and imaging index between the operation group and the conservative group at the last follow-up. In the operation group, there were necrosis of incision margin in 2 cases, pain in calcaneocuboid joint in 1 case and pain in subtalar joint in 1 case. The rest of the patients were satisfied with the orthopedics, the appearance was improved obviously and the symptoms were relieved completely.[Conclusions] For the patients with secondary flatfoot who have no osteoarthritis, the treatment of fusion of the joint and osteotomy of calcaneus can get better early clinical effect.