Provided is an inversion type energy conservation roofing system and a construction method thereof. The system comprises from bottom to top a concrete base layer, a cement mortar screeding layer, a waterproof cushion layer, a heat preservation drainage layer, transverse tile hanging battens and roofing tiles; the heat preservation drainage layer comprises from bottom to top a heat preservation plate layer, a cement mortar protection layer, a longitudinal downstream batten and an aluminum foil coiled material; the longitudinal downstream batten is fixedly connected to the cement mortar protection layer through an anchoring part. According to the inversion type energy conservation roofing system and the construction method thereof, the construction of the system is simple and the construction is convenient; an inversion structure is adopted, a heat preservation layer is laid on a waterproof layer, the cement mortar protection layer is added to cover the heat preservation layer, so that the heat preservation layer and the waterproof layer are protected, destroying of thermal stress, ultraviolet light and other factors is effectively avoided, the heat preservation, thermal insulation and waterproofness effects of the roofing are ensured, and the roofing structure is reinforced; a wooden support is not used, the situation that the anchoring part is knocked in the cement mortar screeding layer and the concrete base layer of a house is avoided, thus the integrity of the screeding layer and a structure layer of the house are guaranteed, the heat preservation effect is better, and the possibility that water seepage occurs in a tack hole place is reduced.