The utility model discloses a building decorative curtain wall, including unit decorative layer and building wall, the inboard of unit decorative layer is equipped with the basal plate, pass through connecting device fixed connection between basal plate and the building wall, connecting device includes first fixing base and second fixing base, first fixing base and second fixing base pass through the bolt and are connected with building wall and basal plate respectively, the outer end middle part of first fixing base is equipped with first connector, the middle part upper end of first connector is equipped with first draw -in groove, the outer end middle part of second fixing base is equipped with the second connector, the lower part of second connector is equipped with the second draw -in groove, the outer end of second draw -in groove is equipped with the U -shaped piece, the utility model discloses a relative building wall of curtain all restricts with removals two directions of level vertical, has increased the steadiness of curtain on building wall, has improved the safety guarantee, and has been convenient for install.