Objective To illustrate the situation of delayed discharge of patients after total knee arthroplasty (TKA) under fast-track (FT) recovery model, and analyze the reasons. Methods We retrospectively analyzed the clinical data of 152 patients who accepted perioperative management under fast-track model from January to December 2014. The reasons for discharging over 72 hours after hospitalization were analyzed. Results Among the 152 patients, 119 were discharged over 72 hours after surgery, and the rate was 78.2%. The main reasons for delayed discharge were pain (32.8%), limited range of motion (31.9%) and unwillingness to be discharged (27.7%), respectively. Conclusion For patients who have undergone TKA, FT model can shorten hospital stay, save expenses, and accelerate postoperative rehabilitation, but there is still much room for improvement.