The invention discloses a laying treatment device of a water supply and drainage pipeline. The device structurally comprises a fixed support plate, an external fixing rod, an external connecting rod,a transverse connecting rod, a hinge structure, a lug, a connecting table, pipeline fixing plates, side clamping frames, a balance connecting rod, a motor, a vertical slide rail structure, an extension rod, a transmission mechanism, a transmission connecting structure, a pressure spring touch structure, an electric switch, a connecting line, a sensing element and an extension connecting frame. According to the device, the vertical slide rail structure, the extension rod and the extension connecting frame are mutually matched; falling time and a position of the pipeline can be controlled freelyand flexibly according to an actual laying situation in a pipeline conveying and distribution process; the operation workload is reduced to a great extent; a progress of the pipeline laying work is ensured; equipment practicability is effectively improved.