The invention provides multifunctional ultrasonic phased array pipeline circumferential weld detection equipment which comprises a main body, a magnetic pressure wheel mechanism, an auxiliary support, a fastening device, a left flaw detection probe bracket, a right flaw detection probe bracket, a left flaw detection probe and a right flaw detection probe, wherein the main body comprises a base, a first slide bar, a second slide bar, a slide bar jackscrew, a left slide bar connecting rack, a right slide bar connecting rack, magnetic wheels and an axle; the fastening device is used for fastening the main body on a pipeline to-be-detected; the magnetic pressure wheel mechanism is arranged between the first slide bar and the second slide bar; the auxiliary support is connected with the first slide bar and the second slide bar of the main body; the flaw detection probe brackets are connected with the flaw detection probes and help the flaw detection probes to detect a weld joint of the pipeline to be detected. The equipment can rotate around the flaw detection pipeline smoothly during pipeline circumferential weld detection, thereby preventing impact of accidental conditions such as vibration on the detection effect, enlarging the application range of the equipment, and improving the flaw detection sensitivity and the detection efficiency.