Objective To study the effects of different marking line preparation techniques on fatigue properties ofrod and compression fatigue properties of posterior spine internal fixation system. Methods According to YY/ T 0119. 4—2014 standard, four-point flexural fatigue test was performed on the spinal rod. According to YY/ T0857—2011, systematic compression fatigue tests under certain stress were carried out on laser marking line rod and dual-color anodized marking line rod. Results Under 715 MPa stress, the fatigue life of the self-made laser marking line rod and the competitor’s laser marking line rod is reduced by 95% and 98% respectively compared with the unmarked rod, and the fatigue strength of the laser marking line rod decreased by 54% from 742 MPa to 342 MPa, compared with unmarked rod. The fatigue life and strength of the dual-color anodized marking line rod are similar to that of the unmarked rod. The compression fatigue strength of the dual-color anodized marking line rod system was 20% higher than that of the laser marking rod. Conclusions Laser preparation of marking line significantly reduces the fatigue performance of the spinal rod and the compressive fatigue strength of the system. The improved dual-color anodized marking line technology has no effects on the fatigue performance,and can effectively reduce the risk of clinical fracture, providing a reference for the performance improvement and process development of the spinal rod.