Objective To explore the application value of CT classification of lumbar spinal stenosis(LSS)in selecting endoscopic decompression surgery approach.Methods The clinical data and CT imaging materials of 300 patients with LSS,who received percutaneous endoscopic decompression surgery from March 2018 to December 2024 were selected from Hengshui Municipal People's Hospital in Hebei(Halison International Peace Hospital),were retrospectively analyzed.Preoperative CT scan was performed in all patients.Taking endoscopic classification as the golden standard,the consistency between CT classification results and endoscopic classification results was assessed by Kappa consistency analysis.The effect of surgery of different approaches for percutaneous endoscopic decompression surgery was compared.Results CT diagnostic classification of type Ⅰ LSS was obtained in 87 patients(among them 3 patients with type Ⅲ LSS were misdiagnosed as type Ⅰ LSS),type Ⅱ LSS in 141 patients and type ⅢLSS in 72 patients,the total diagnostic accuracy rate was 97.67％.Using endoscopic classification as the gold standard,the Kappa values for CT diagnosis of type Ⅰ,type Ⅱ and type Ⅲ were 0.975,1.000 and 0.973,respectively.According to the CT classification results,all 300 patients successfully selected different surgical approaches to complete the surgery,and their clinical symptoms were significantly relieved without significant complications.After surgery,the Oswestry disability index(ODI)and visual analogue scale(VAS)scores of leg/lower back in patients with different LSS types showed a decreasing trend(P＜0.05).After treatment,the total frequency of taking non-steroidal drugs was significantly lower than that before surgery(P＜0.05).Conclusion The classification of LSS is highly consistent between CT scan and endoscopic examination,which is of great value for the selection of percutaneous endoscopic decompression surgery approach.