Objective To investigate the effect of allogeneic massive bone graft and locking plate internal fixation in the treatment of subtalar articular surface collapse with obvious bone defects. Methods A retrospective case-control study was conducted to analyze the clinical data on 52 patients with subtalar articular surface collapse and obvious bone defects treated between April 2017 and December 2019. These patients were divided into the open reduction and internal fixation plus allogeneic massive bone graft group (observation group) and open reduction and internal fixation plus allogeneic small bone strip or calcium sulfate bone particle bone graft group (control group) according to treatments, with 26 patients in each group. Patients in the observation group began to walk with full weight 8 weeks after operation and those in the control group 12 weeks after operation. All the patients were followed up for 12-24 months. The changes of the B hler angle and Gissan angle of the calcaneus were observed before operation, 2 days and 12 months after operation. The function of feet in the two groups before and after operation was followed up and compared. Results The B hler angle and Gissan angle of the two groups were significantly improved after operation, but there was no significant difference in the B hler angle or Gissan angle between the two groups (P<0.05). There was no significant difference in days of hospital stay, postoperative complications or healing time of fractures between the two groups. According to the Maryland's foot function scoring standard, the excellent and good rate of the observation group was 92.31%, higher than 84.62% of the control group(P<0.05). Conclusions Treatment of calcaneal subtalar articular surface collapse with obvious bone defects with allogeneic massive bone graft support and locking plate internal fixation can ensure good therapeutic effect.