A horizontal grounding body of a three-segment type structure with 120-degree branches is characterized in that a first electrode 1, a second electrode 2 and a third electrode 3 are in a same horizontal plane and are in fixed connection of 120-degree included angles, the lengths of the second electrode 2 and the third electrode 3 are same, and the length of the first electrode is 1-2 times of the length of the second electrode 2; a dispersed current is injected from the initial end of the first electrode and diffuses to the surrounding soil via the second and third electrodes. The horizontal grounding body of the three-segment type structure with the 120-degree branches of the utility model is simple in structure and small in occupied area, is convenient to install, and enables the impulse grounding resistance to be reduced effectively.