Objective To evaluate the effect of pneumatic tourniquet on perioperative period of total knee arthroplasty (TKA). Methods The perioperative period data of 116 patients over 60 years old with severe knee osteoarthritis treated with TKA between January 2018 and January 2019 were retrospectively analyzed. According to whether pneumatic tourniquet was used during operation, the patients were divided into trial group (49 cases, pneumatic tourniquet was not used during operation) and control group (67 cases, pneumatic tourniquet was used during operation). There was no significant difference in gender, age, body mass index, lesion side, disease duration, and preoperative hemoglobin between the two groups (P>0.05). The operation time, actual total blood loss, overt blood loss, hidden blood loss, and percentage of hidden blood loss, knee swelling at 3 days after operation, and range of motion of knee at 2 weeks after operation were recorded and compared between the two groups. Results The operation time of the trial group was significantly longer than that of the control group (t=14.013, P=0.000). The actual total blood loss, hidden blood loss, and percentage of hidden blood loss in the trial group were significantly lower than those in the control group (P<0.05); there was no significant difference in the overt blood loss between the two groups (t=−1.293, P=0.200). The knee swelling degree in the trial group was significantly slighter than that in the control group at 3 days after operation, and the range of motion of knee in the trial group was significantly better than that in the control group at 2 weeks after operation (P<0.05). Conclusion Pneumatic tourniquet can reduce the operation time of TKA significantly. However, it may increase the hidden blood loss and knee swelling, and negatively impact the recovery of knee function in the early postoperative stage of TKA.