ObjectiveTo explore the safety of ultrasonic osteotome used in posterior cervical laminectomy decompression surgery and its effect on surgical outcome. Methods A clinical data of 52 patients with ossification of posterior longitudinal ligament of cervical spine (C-OPLL) undergoing posterior cervical laminectomy decompression and fusion (PCLDF) between April 2013 and April 2017 was retrospectively analysed. The patients were divided into two groups according to whether using the ultrasonic osteotome during operation: group A (20 cases, ultrasonic osteotome group) and group B (32 cases, traditional gun-clamp decompression group). There was no significant difference in gender, age, body weight, height, preoperative hemoglobin, and Japanese Orthopedic Association (JOA) score between the two groups (P>0.05). The operation time, intraoperative blood loss, postoperative drainage volume, hospitalization time, complications, hemoglobin at 1 day after operation, and JOA score at 6 months after operation were recorded and compared between the two groups, and the improvement rate of JOA was calculated. Results The operation time and intraoperative blood loss in group A were significantly less than those in group B (P<0.05); there was no significant difference in the drainage volume and hospitalization time between the two groups (P>0.05). The hemoglobin of group B was slightly higher than that of group A at 1 day after operation, but there was no significant difference between the two groups (t=–1.260, P=0.214). All the patients were followed up 6-10 months (mean, 7.6 months). No serious complications such as C5 nerve paralysis, dural tear, infection, epidural hematoma, deep venous thrombosis, pulmonary embolism, transfusion allergy, or shock occurred during and after operation. The JOA scores of the two groups were significant improved at 6 months after operation when compared with preoperative scores (P<0.05), and there was no significant difference in JOA score and improvement rate between the two groups at 6 months after operation (P>0.05). Conclusion Compared with the traditional gun-clamp decompression, the effectiveness of PCLDF in treatment of C-OPLL by using ultrasonic osteotome is comparable, but the latter can effectively reduce the operation time and blood loss.