Objective: To investigate the safety and efficacy of “modified cocktail” in single-level posterior lumbar interbody fusion (PLIF). Methods: A total of 60 patients with single-segment PLIF from January 2018 to February 2019 in the spinal surgery department of Xiangtan Central Hospital were selected as subjects. They were randomly divided into a cocktail group (group A, n=30) and a saline group (group B, n=30). The 24-hour drainage volume and total drainage volume, hemoglobin value (HB), hematocrit (Hct), dimer value, postoperative deep venous thrombosis, VAS pain score at 4, 8, 12, 24 and 48 hours were observed before and after the intervention. The Changes of heart rate and blood pressure before intervention and were also observed immediately, 5, 10 and 30 minutes after intervention. The adverse events after operation were observed. The average follow-up time was 1 month. Results: There were significant differences in 24 h drainage volume, total drainage volume and HB and Hct on the 1st and 3rd day after operation between the two groups (P<0.05), but there was no significant difference in intraoperative blood loss between the two groups (P>0.05). There was no blood transfusion after operation in both groups. Compared with group B, VAS pain score in group A was lower at 4, 8 and 12 hours postoperatively (P<0.05), and VAS pain score at 24 and 48 hours postoperatively had no significant difference. There were no significant differences in systolic blood pressure, diastolic blood pressure, heart rate difference, preoperative and postoperative plasma D-dimer values between the two groups (P>0.05). There were no adverse events such as deep venous thrombosis of lower extremities in both groups, and delayed wound healing occurred in 1 case in group A and 1 case in group B, with no significant difference between the two groups. Conclusion: Local application of “modified cocktail” can effectively reduce the blood loss after lumbar posterior interbody fusion, reduce the pain of incision in the early stage, and do not increase the risk of deep vein thrombosis of lower limbs.