Vacuum sucker-type small-diameter tube inner wall water immersion ultrasonic inspection device

The invention belongs to the technical field of pressure vessel small-diameter tube inner ultrasonic detection and especially of nuclear reactor pressure vessel small-diameter tube inner ultrasonic detection and relates to a vacuum sucker-type small-diameter tube inner wall water immersion ultrasonic inspection device. A circumferential sleeve is provided with a hoisting head, a circumferential sleeve support and a circumferential motor, a vacuum sucker is connected to the circumferential sleeve support, a circumferential central spindle is located in the circumferential sleeve and rotates relative to the circumferential sleeve, the front end of the circumferential central spindle is provided with a tensioning cylinder, a stator of an axial motor, one end of a guide shaft and a tooth ring, the tooth ring and a gear of the axial motor form a gear ring pair, one end of a screw is connected to a rotor of the axial motor, an intermediate support sleeve is provided with an intermediate support cylinder and an intermediate support leg, an intermediate support top block is connected to a piston rod of the intermediate support cylinder and an intermediate support central spindle is located in the intermediate support sleeve. The device realizes detection from the pipe inner wall. The water immersion ultrasonic detection is not influenced by surplus height of a welding line and realizes a pipe weld nondestructive test.