Objective:To explore the clinical efficacy of DELTA endoscopic lumbar interbody fusion for the treatment of mild to moderate, single segment lumbar spondylolisthesis.Methods:A retrospective analysis was conducted on the clinical data of 48 surgical cases of grade Ⅰ to Ⅱ lumbar spondylolisthesis admitted to the First Affiliated Hospital of Hunan University of Traditional Chinese Medicine from February 2020 to March 2022. Among them, 24 cases treated with DELTA endoscopic lumbar interbody fusion surgery were classified as the DELTA group, and 24 cases treated with traditional minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) surgery were classified as the MIS-TLIF group. Two groups of patients were compared in terms of perioperative indicators (surgical time, postoperative drainage volume, incision length, hospital stay), clinical efficacy [Visual Analogue Scale (VAS) score for low back and leg pain, lumbar Japanese Orthopaedic Association Scores (JOA), improved MacNab standard excellence rate], and lumbar fusion rate (Bridwell intervertebral fusion grade).Results:The DELTA group had longer surgical time than the MIS-TLIF group, and the postoperative drainage volume, incision length, and hospital stay were all lower than the MIS-TLIF group, with statistically significant differences (all P<0.05). The VAS score of lower back and leg pain and lumbar JOA score of the two groups of patients at 1 week, 3 months, and the last follow-up were significantly improved compared to those before surgery (all P<0.01), and the DELTA group had better VAS score of lower back and leg pain and lumbar JOA score at all time points after surgery than the MIS-TLIF group, with statistically significant differences (all P<0.05). The improved MacNab standard was used to evaluate the efficacy of the two groups of patients at the last follow-up after surgery, and there was no statistically significant difference in the excellent and good rates ( P>0.05); There was no statistically significant difference ( P>0.05) in the fusion rate between the two groups. Conclusions:DELTA endoscopic lumbar interbody fusion has a significant therapeutic effect on lumbar spondylolisthesis, with the advantages of small surgical incision and fast recovery; After crossing the DELTA endoscopic learning curve and optimizing surgical procedures, this technology can become an alternative to MIS-TLIF technology.