Objective To explore the clinical value of neurography and nerve root sealing in treatment of multilevel lumbar spinal stenosis with lumbar instability using Endo?P/TLIF. Methods A total of 60 patients with multi?segment lumbar spinal stenosis and lumbar instability hospitalized in our hospital were included in this study From January 1， 2022 to June 21， 2022. All patients underwent nerve root closure angiography before surgery to confirm the responsible segments， and then the responsible segments were treated with Endo?P/TLIF. The patients were followed up for 6 months. The basic information on the age， gender， course of disease， surgical time， intraoperative bleeding， hospitalization time， and off?bed ambulation time was collected. Then the data on VAS score， ODI score， JOA score， lumbar lordosis angle， intervertebral height， dural cross?sectional area， sacral inclination angle， pelvic projection angle， and pelvic inclination angle before， right after， 3 months and 6 months after the operation were calculated. The number of responsible segments indicated by MRI and confirmed by nerve root closure angiography and the number of the single segment， double segments， 3 segments， and above finally decompressed were statistically analyzed. Results All patients went through the surgery safely. During the 6?month follow?up， one patient did not return to the hospital for consultation on time， and one patient was out of contact. Finally， the follow?up data of 58 patients were completely collected for statistical analysis. Fifty?five cases were remarkably improved， 2 better， and 1 moderately， 6 months after the operation， with a total effectiveness rate of 100%. The number of unilateral and bilateral single responsible segments confirmed by nerve root angiography and sealing was significantly larger than by MRI （P < 0.05）， but the number of unilateral and unilateral double， or multiple responsible segments was significantly smaller （P < 0.05）. There were statistically significant differences in terms of postoperative VAS score， ODI score， JOA score， VAS score， ODI score， JOA score， lumbar lordosis angle， intervertebral height， dural cross?sectional area， sacral inclination angle， pelvic inclination angle as compared to the preoperative data （P ? 0.05）. The pelvic projection angle was insignificantly improved as compared to the preoperative condition （P ? 0.05）. Conclusion The accurate diagnosis with selective neurography and nerve root sealing improves the confirmation of responsible nerve segments before operation. Base on the accurate diagnosis， multi?segment lumbar spinal canal stenosis with lumbar instability can be effectively treated with Endo?P/TLIF， the responsible segment decompressed， trauma and bleeding reduced， hospital stay shortened， spinal physiological curvature well recovered， and clinical efficacy improved. Therefore， the method is worthy of extensive application in clinical practice.