The invention belongs to the reformation field of damaged cooling walls of blast furnaces, relating to a pore channel cooling method of a damaged cooling wall of a blast furnace and a device thereof. The damaged cooling wall is independently separated, a metal corrugated flexible pipe are respectively inserted into a water inlet pipe and a water outlet pipe of the cooling wall, the front end of each metal corrugated flexible pipe is blocked by a core plug, metal corrugated flexible pipes with smaller pipe diameters are then inserted in the metal corrugated flexible pipes, the front ends of the flexible pipes are blocked by core plugs, a plurality of pores are arranged on the core plugs, slurry with high heat conduction factor is filled between the cooling wall and the large metal corrugated flexible pipes, cooling water passes through a cavity formed between the large and small metal corrugated flexible pipes, passes through the pore channels of the small metal corrugated flexible pipes and then flows out of the small metal corrugated flexible pipes, and then the cooling effect is achieved. The invention can improve the phenomena that one part of the cooling pore channels of the cooling wall is burnt out or the channels are small, solve the problem of water leakage, ensure cooling intensity, prolong the service life of the damaged cooling wall and solve a thorny problem restricting the production of the blast furnace.