The invention discloses an ultrasonic detection device for insulation tube for live working, and relates to the ultrasonic detection device. Currently, accurate detection of the ultrasonic detection device on site is not ideal. The invention comprises a wedge, an ultrasonic probe, a base and an ultrasonic detector. The bottom of the wedge is concave inward to form a penetrated concave arc-shaped surface matched with the detecting rod, the top of the wedge is provided with the ultrasonic probe, and the arc-shaped limiting portion is provided with the side of the wedge, wherein the arc-shaped limiting portion is provided with an elastic pressing member; the base is cylindrical, and the inner holes are stepped holes, comprising a large-diameter hole and a small-diameter hole; the large-diameter hole is matched with the limiting portion of the wedge; the small-diameter hole is provided with a fastener; the arc-shaped limiting portion of the wedge is inserted into the large-diameter hole ofthe base, and the elastic pressing member is pressed against a hole wall of the large-diameter hole; the arc-shaped limiting portion slides along the hole wall of the large-diameter during the detection, so that the wedge rotates 360 degrees around the detecting rod to realize circumferential detection. The ultrasonic detection device for insulation tube for live working is small in size, easy tocarry, and suitable for the defect accurate detection of the insulation tube on site.