The utility model relates to building pipelines, particularly to a water supply, water drainage and circuit combined passage for buildings, which realizes the combined function of water supply, water drainage and cable laying within one pipeline. The water supply, water drainage and circuit combined passage for buildings includes a passage body, a water drainage passage, a water supply passage and an electric wire passage, wherein the passage body is drum-shaped, made of PVC, and is internally divided into two equal parts by a transverse baffle, the semi-circle in the cross section is a water drainage passage, and another transverse baffle is arranged in the other semi-circle, and is used for dividing the semi-circle into a water supply passage and an electric wire passage. The combined passage can be used for the installation of water supply, water drainage and power supply through one construction, thereby saving manual labor and material.