A heat pump system includes a main heat pump system, a heat retaining layer and a reflecting layer coated on an partial inner surface of a building, a directly expanded strong cool-heat radiation plate having a distance from the reflecting layer, a heat radiating layer located at a side of the directly expanded strong cool-heat radiation plate and having a distance from the directly expanded strong cool-heat radiation plate, a buffer plate disposed between the heat radiating layer and the directly expanded strong cool-heat radiation plate, an anti-condensation trough disposed below the directly expanded strong cool-heat radiation plate. A sealed cavity is enclosed by the heat radiating layer and a wall surface, and the wall surface is formed by a combination of the partial inner surface of the building, the heat retaining layer and the reflecting layer, and, the sealed cavity is filled with air.