〔Abstract〕 Objective To study the long-term clinical efficacy of posterior cervical single open door enlarged spinal canal plasty in the treatment of multi segment cervical spinal stenosis. Methods A retrospective analysis was made on 120 patients with multi segment cervical spinal stenosis admitted to Zhengzhou Orthopedic Hospital from March 2016 to March 2019. All patients were treated with posterior cervical single open door enlarged spinal canal plasty. The visual analogue scales (VAS), the Japanese Orthopaedic Association scores (JOA), the Oswestry dability index (ODI), Cobb angle, and cervical curvature of patients before and after treatment were compared. The incidence of postoperative complications, the recurrence rate of spinal cord and nerve injury symptoms, and the excellent and good rate of patients were statistically analyzed. Results The total complication rate was 14.17 %, the total recurrence rate was 4.17 %, and the excellent and good rate was 95.83 %. After the treatment of posterior cervical single open door enlarged spinal canal plasty, the VAS score, Cobb angle and cervical curvature of the patients were decreased at each time period compared with that before operation, with statistically significant difference (P < 0.05); compared with 2 weeks after operation, the VAS score, Cobb angle and cervical curvature of the patients were decreased at 6 months after operation, with statistically significant difference (P < 0.05); compared with 6 months after operation, the VAS score of patients was decreased at 1 year after operation, with statistically significant difference (P < 0.05); compared with 1 year after operation, the VAS score of patients at 2 years after operation was lower, with statistically significant difference (P < 0.05). After the treatment of posterior cervical single open door enlarged spinal canal plasty, the JOA score of patients increased and the ODI score were decreased at each time period compared with that before operation, with statistically significant difference (P < 0.05); compared with 2 weeks after operation, the JOA score of patients was increased and the ODI score was decreased at 6 months after operation, with statistically significant difference (P < 0.05); compared with 6 months after operation, the JOA score of patients was increased and the ODI score was decreased at 1 year after operation, with statistically significant difference (P < 0.05); compared with 1 year after operation, the JOA score of patients was increased and the ODI score was decreased at 2, 3 and 4 years after operation, with statistically significant difference (P < 0.05). Conclusion The long-term clinical effect of posterior cervical single open door enlarged spinal canal plasty in the treatment of multi segment cervical spinal stenosis is significant, which can effectively reduce the symptoms of numbness, pain and weakness of cervical spine and limbs, and improve the quality of life of patients. Axial pain and C5 nerve root paralysis are more likely to occur after operation, but the overall incidence of complications is low, and most of the complications have not affected the final curative effect after active and appropriate treatment.