Abstract: In the building water supply and drainage system, copper alloy pipes have high strength and corrosion resistance. In order to extend the service life of copper alloy pipes, the arc welding process of copper alloy pipes for building water supply and drainage is studied. H65 copper alloy pipe with outer diameter of 50mm and wall thickness of 3mm is selected as the base material, and MONEL187 welding rod is used to carry out arc welding operation with inverter DC arc welding machine. The designed welding currents are 100A, 110A, 120A, 130A and 140A respectively. The specimens were subjected to two kinds of post-welding heat treatment at 480℃×120min and 620℃×120min at each current. The tensile properties, friction and wear properties and corrosion resistance properties of welded copper alloy pipeline specimens were tested to analyze the changes in the properties of the specimens under different welding conditions. The results show that different welding parameters and heat treatment conditions have great influence on the properties of copper alloy pipes. Among them, the combination of welding current 120A and heat treatment process of 480℃×120min can guarantee the highest tensile stress of the specimen. Under this welding process, the wear rate of the specimen is only 0.95×10⁻⁸g · (r · N)⁻¹, and the specimen is less prone to wear and corrosion. Welding current 120A and heat treatment process of 480℃×120min can effectively guarantee the welding quality of copper alloy pipes.