Fence supporting device suitable for external slope body of foundation pit

The utility model discloses a fence supporting device suitable for an external slope body of a foundation pit, and belongs to the technical field of foundation pit supporting. The fence supporting device suitable for the external slope body of the foundation pit comprises a first longitudinal supporting column and a second longitudinal supporting column, and the first longitudinal supporting column is connected with a first limiting sliding plate in a sliding mode; a second limiting sliding plate is connected to the second longitudinal supporting column in a sliding mode. A first limiting guide rod and a second limiting guide rod are respectively fixed on the first limiting sliding plate and the second limiting sliding plate; the first limiting guide rod is connected with a first limiting clamping block; a cylindrical connecting rod is arranged between the first limiting sliding plate and the first limiting clamping block; a limiting guide hole is formed in the first limiting clamping block; the first limitin