The utility model discloses a water seepage prevention mounting structure for floor heating. The composite heat preservation layer comprises a composite heat preservation layer body, the composite heat preservation layer is laid on the ground. An embedded layer is laid on the composite heat preservation layer. A water guide main pipe is buried in the pre-buried layer, and a pre-buried groove is formed above the pre-buried layer; the pre-buried groove is of a snake-shaped structure, and anti-seepage porcelain tubes are evenly installed in the pre-buried groove. The seepage-proofing ceramic pipeis formed by splicing a plurality of sets of ceramic pipes, a heat preservation pipeline is laid in the seepage-proofing ceramic pipe, the seepage-proofing ceramic pipe is communicated with the waterguide main pipe, a pea gravel concrete layer is laid on the heat preservation pipeline, sealing layers are laid on the two sides of the pea gravel concrete layer, a moisture absorption layer is laidon the pea gravel concrete layer, and a floor is laid on the moisture absorption layer. According to the utility model, the moisture absorption layer is paved below the floor, so that sucked air in aheater can be absorbed to a certain extent, moisture contact with the floor is reduced, and the purpose of protecting the floor is achieved.