The utility model discloses a building fastening device which comprises an upper fastening piece and a lower fastening piece, the upper fastening piece and the lower fastening piece are made of the same material, the lower fastening piece comprises a steel base plate, the outer surface of the steel base plate is provided with a material compression-resistant layer, the outer surface of the material compression-resistant layer is provided with a
rust-resistant layer, and the outer surface of the
rust-resistant layer is provided with an anti-
corrosion layer. And a protective
coating layer is arranged on the outer surface of the anti-
rust layer. The beneficial effects of the utility model are that through the arrangement of the aluminum plating layer and the
zinc plating layer, the aluminum plating layer and the
zinc plating layer have the greatest advantages of excellent
corrosion resistance, painting performance, decoration performance and good
formability, the
corrosion resistance and corrosion resistance of the upper
fastener and the lower
fastener are increased, the service life of the upper
fastener and the lower fastener is further prolonged, and the service life of the upper fastener and the lower fastener is prolonged. Through the arrangement of the material compression-resistant layer and the
alloy material layer, the use strength of the upper fastener and the lower fastener is improved, the phenomenon that the upper fastener and the lower fastener are fractured after being used for a long time is prevented, and the service life of the upper fastener and the service life of the lower fastener are prolonged.