The invention relates to a suppressible horizontal drawing flat window which comprises a window frame; the window frame is internally provided with a lower rail, an upper rail matched with the lower rail, and a window body constructed on the lower rail and the upper rail; the rails bend from the space allowed by the window frame and stretch outwards so that the window body which is positioned in the middle of the window frame when being closed leaves the space allowed by the window frame by the guidance of the upper rail and the lower rail when being started, therefore, the space is not covered by the window body and the area of the space can be used efficiently.