The utility model relates to a building curtain wall, including concrete placement layer and curtain board, be provided with the multiunit fossil fragments in the concrete placement layer, fossil fragments interconnect the formation framework, the curtain board sets up in the framework, and curtain board below is provided with the heat preservation, scribble the one deck clean layer on the curtain board surface, the clean layer outside is by interior and set gradually the confining bed outward, antistatic backing and photocatalysis layer, the fossil fragments inboard is provided with slides the groove, and current groove has been seted up to the fossil fragments below, it is provided with the slider to slide the inslot, be connected with the bracing piece between the slider, the bracing piece below is provided with the mount pad, the mount pad below is provided with the scraper blade, and the mount pad top is provided with the washing liquid box body, the utility model discloses simple structure, just thermal -insulated effectual.