The invention discloses a fireproof profile steel structure for a building. The fireproof profile steel structure comprises a bottom plate, a protective plate, a cooling liquid plate, a resin heat-insulation plate, fixing plates, screw rods, screw holes, a steel plate, convex blocks, first vertical grooves, first vertical plates, second vertical plates, second vertical grooves, a groove and a topplate. The fireproof profile steel structure has the beneficial effects that the resin heat-insulation plate is arranged on the surface of the bottom plate, the top of the resin heat-insulation plateis fixedly connected with the convex blocks, and the two sets of first vertical grooves are formed in the edges of the side walls of the resin heat-insulation plate; and the screw holes are formed inthe side walls of the convex blocks and the side walls of the resin heat-insulation plate, the fixing plates are arranged on the edge of the bottom plate, and the screw holes are formed in the side walls of the fixing plates; and the screw holes of the resin heat-insulation plate correspond to the screw holes of the fixing plates, the screw rods are screwed in, thus the resin heat-insulation platecan be fixed, and the resin heat-insulation plate achieves the heat-insulation and protection effects.