Inverted flat roof composite waterproof heat preservation structure and construction method thereof

The invention relates to the technical field of roof waterproofing, and discloses an inverted flat roof composite waterproof heat preservation structure. The inverted flat roof composite waterproof heat preservation structure comprises a roof layer, a heat preservation layer, a waterproof layer and a protective layer which are sequentially arranged, the heat preservation layer comprises a plurality of mutually connected heat preservation plates, mounting grooves are formed in one sides of the heat preservation plates, and horizontal inserting plates are arranged at the edges of the sides, awayfrom the mounting grooves, of the heat preservation plates; and inserting grooves matched with the inserting plates are formed in the two side walls of the mounting grooves, first positioning piecesfor fixing the horizontal positions of the inserting plates are arranged in the mounting grooves, horizontal pressing plates are formed at the edges of the tops of the heat preservation plates, transverse grooves matched with