Fireproof steel structure of green building

The invention discloses a green building fireproof steel structure, which belongs to the technical field of steel structures, and comprises a first connecting pipe, a second connecting pipe is arranged in the first connecting pipe, a gap is arranged between the first connecting pipe and the second connecting pipe, the bottom surface of the second connecting pipe is fixedly connected with a water tank, and the water tank is fixedly connected with the inner wall of the first connecting pipe. A fireproof mechanism is arranged between the second connecting pipe and the first connecting pipe and communicates with the water tank, and a collecting mechanism is arranged on the top face of the second connecting pipe and communicates with the water tank through the second connecting pipe. And when the steel structure is on fire, fire extinguishing and cooling are conducted on the outer side and the inner side of the first connecting pipe through the fireproof mechanism, the collecting mechanism is used for collecting r