Objectives: To investigate the effect of cage placement direction on the clinical efficacy and fusion rate of each zone in patients after lumbar spine fusion. Methods: The medical records of 57 patients with lumbar spinal stenosis and lumbar intervertebral disc herniation treated with TLIF technology from March 2013 to August 2017 were retrospectively analyzed. There were 25 males and 32 females; the age ranged from 25 to 78 years old, with an average of 57.9 years old. A total of 57 segments of lumbar interbody fusion were performed. According to the method of cage placement, they were divided into a lateral implantation group (lateral group, 23 cases) and an oblique implantation group (oblique implantation group, 34 cases). The age, gender, bone mineral density, body mass index (BMI) and surgical segment of the two groups were recorded, and the Oswestry disability index (ODI) and pain visual analogue scale (visual analogue scale) were used before operation and at the last follow-up. analog scale, VAS). CT thin-section scan was used to evaluate the fusion situation of each zone in the fusion level. Results: There was no significant difference in age, gender，bone mineral density, BMI and surgical segment between the two groups (P>0.05). The preoperative ODI and VAS scores were not statistically significant (P>0.05); both groups were followed up for more than 24 months, and the ODI and VAS scores at the last follow-up were significantly improved compared with those before surgery (P <0.05). In the comparison of cage fusion rate in each area of the transverse group, the fusion rate of the contralateral area of decompression was lower than that of the other four areas, and the difference was statistically significant (P < 0.005). And the difference was statistically significant (P < 0.005). Comparing the two groups, the fusion rate behind the cage in the transverse group was higher than that in the oblique group, and the difference was statistically significant (P < 0.05). Conclusion: Both lateral and oblique placement of interbody cages in lumbar fusion surgery can achieve satisfactory results. There is no significant difference in the fusion rate between obliquely placed cages and laterally placed cages, but the fusion rate of lateral cages behind the cages is higher.