The invention discloses a waterproof and dampproof type steel structure for a building. The waterproof and dampproof type steel structure comprises a steel structure outer layer, a plurality of steelstructure interlayers and a plurality of waterproof coatings. The multiple steel structure interlayers are horizontally and fixedly arranged in the steel structure outer layer, the outer surface of the steel structure outer layer and the outer surfaces of the multiple steel structure interlayers are evenly coated with the multiple waterproof coatings correspondingly, and the waterproof coatings are made of polyvinyl chloride. In this way, according to the waterproof and dampproof type steel structure for the building, the outer surface of the steel structure outer layer and the outer surfacesof the steel structure interlayers are evenly coated with the waterproof coatings, so that the waterproof and dampproof functions are achieved; and the structure is novel, the performance is stable, the waterproofness is good, safety and reliability, convenience and practicability are achieved, and wide market prospects in popularization of the waterproof and dampproof type steel structure for thebuilding are achieved.