Objective To investigate the perioperative analgesic effect of ultrasound-guided bilateral thoracolumbar interfascial plane block （TLIPB） in patients with discogenic low back pain （DLBP） undergoing percutaneous transforaminal endoscopic discectomy （PTED）. Methods Fifty-seven patients with discogenic low back pain admitted to the First Affiliated Hospital of Anhui Medical University from January 2022 to April 2022 were randomly divided into group A （control group）with 28 patients and group B （ultrasound-guided bilateral thoracolumbar interfascialinterfacial plane block group） with 29 patients. The differences of visual analogue scale （VAS） at rest and turning over were compared between the two groups preoperative （t₀）， 2 hours postoperative （t₁）， 6 hours postoperative （t₂）， 12 hours postoperative （t₃） and 24 hours postoperative （t₄）. The differences of quality of recovery-15 scores （QoR-15） were compared between the two groups preoperative and 24 hours postoperative. The changes of mean arterial pressure （MAP） and heart rate （HR） were compared between the two groups after entering the operating room （T₀）， at the time of skin incision （T₁）， at the time of foraminoplasty （T₂）， at the time of the most severe pain recognized by the surgeon （T₃）， and at the end of the operation （T₄）.Adverse events were recorded during the operation and within 24 hours postoperative. Results All patients successfully completed the operation and ultrasound-guided bilateral TLIPB， without intervertebral space infection， spinal cord， nerve root and vascular injury， and serious complications such as nausea and vomiting. VAS scores at rest and turning over and QoR-15 scores at 24 hours postoperative were significantly lower than preoperative in the two groups （P < 0.05）. There was no significant difference in VAS scores between the two groups at rest at preoperative and postoperative time points （P > 0.05）. There were significant differences in VAS scores at 2 hours， 6 hours and 12 hours postoperative between the two groups （P < 0.05）. There were significant difference in QoR-15 scores between the two groups at preoperative and 24 hours postoperative （P > 0.05）. There was a significant difference in QoR-15 scores between the two groups at 24 hours postoperative （P > 0.05）. There were significant differences in MAP and HR between the two groups at the time of foraminoplasty （T₂） and at the time of the most severe pain recognized by the surgeon （T₃）（P< 0.05）. Conclusions Ultrasound-guided bilateral thoracolumbar interfascial plane block can effectively relieve the pain after PTED， reduce the occurrence of perioperative stress response and adverse events， accelerate the postoperative rehabilitation of patients， and shorten the postoperative duration of hospitalization.