Objective: To investigate the short-term effect of unilateral biportal endoscopy (UBE) and open surgery in lumbar fusion. Methods: Retrospective analysis was performed on 56 patients with lumbar degenerative diseases admitted to our hospital from January 2019 to June 2020, and they were divided into unilateral biportal endoscopy groupand traditional open surgery group according to the surgical methods. Among them, there were 21 cases in the UBE group and 35 cases in the traditional open surgery group. The operative time、hospitalization cost, incision length、postoperative drainage volume, treatment cost、VAS score、 Ostry Disability Index (ODI)、modified MacNab standard score, and incidence of complications were compared between the two groups. Results: The operation time and hospitalization cost of UBE operation group were higher than those of traditional operation group. However, in terms of postoperative drainage volume and incision length, the UBE operation group was significantly better than the open operation group. The early postoperative pain was more obvious in the UBE surgery group than in the open surgery group. During the six-month follow-up, there was no significant difference in the excellent and good rates of modified MacNab score between the two groups. There was no significant difference in the incidence of complications between the two groups. Conclusion: Compared with the traditional open surgery in the treatment of lumbar degenerative diseases, UBE has the advantages of less trauma and faster recovery. It has the characteristics of wide field of vision, simple requirements of surgical instruments and smooth learning curve. It is worth popularizing in clinical practice.