Crest fixed metal roof structure and construction method thereof

The invention discloses a crest fixed metal roof structure and a construction method thereof. The structure comprises roof steel beams, roof main purlines, roof secondary purlines, metal roof slabs, vapor barriers, Z-shaped keels, thermal insulation layers, waterproof and vapor-permeable membranes (8) and roof boards. Cross sections of the metal roof bottom plates comprise alternately arranged bottom plate crest sections and bottom plate trough sections, the metal roof bottom plates and the roof secondary purlines are fixedly connected through first connecting parts penetrating through the metal roof bottom plates and the roof secondary purlines, the first connecting parts corresponding to the positions of the bottom plate crest sections are transversely arranged at intervals, the Z-shapedkeels, the vapor barrier membranes and the roof secondary purlines are fixedly connected through second connecting parts penetrating through the Z-shaped keels, the vapor barrier membranes and the roof secondary purlines, an