Sub-synchronous oscillation is a fault that seriously threatens the safe and stable operation of a power system, and research has been carried out around the generation mechanism and suppression measures. However, there is no related literature on the influence of different line models on simulation analysis. In order to explore this influence of different line models and their respective analysis application scope during simulation analysis, by comparing the damping levels of different line models the influence of each line model on the simulation analysis of series-compensated sub-synchronous oscillation is summarized. The electromagnetic transient simulation software ATP-EMTP is used for simulation verification. The results show that the damping levels of the concentrated inductor resistance model, the π-type model, and the Bergeron model are equivalent. The JMarti model as the most accurate model provides the largest damping level. When performing a simplified analysis, the concentrated inductor resistance model can be used to quickly draw conclusions; and in cases where refers to inhibit device design, the JMarti model can be used prudently. This work is supported by the National Natural Science Foundation of China (No. U1766208).