Abstract: In restricted areas of corridors, in order to save corridor resources, ultra-high voltage direct current lines and grounding electrode lines are usually installed on the same tower. After the installation of the common tower, the electromagnetic coupling between the high-voltage pole line and the grounding pole line makes the lightning protection performance of the line more complex. This article calculates and analyzes the lightning protection performance of DC pole lines and grounding pole lines under independent and shared tower installation schemes. The results show that due to the shielding protection of the grounding pole lines, the flashover rate of the pole lines in the shared tower installation scheme is lower than that in the independent installation scheme.