The utility model discloses a sacrificial anode used for controlling corrosion of an outer wall of a large diameter pipeline, which is used for a protecting device (3) of a sacrificial anode used for controlling corrosion of an outer wall of a large diameter pipeline. The sacrificial anode is characterized in that: the sacrificial anode (302) used for controlling corrosion of the outer wall of the large diameter pipeline is of a rod shape, and the ratio between the length and the external diameter of the cross section is 3 to 10. The sacrificial anode can ensure the continuity of pipeline jacking construction, greatly saves mounting workload and mounting cost, can realize long-term protection through a construction, meets requirements on durability of large engineering construction, and has foreseeable economic value and social value in engineering application.