Compression-type traction device for avoiding post-contraction of loose tube

The invention relates to special equipment for avoiding post-contraction of a loose tube in the production field of loose tubes. The special equipment comprises a swing arm, a rotary shaft, a tension sensor, a bearing seat, an air cylinder, a servo motor, a driving wheel system and a driven wheel system, wherein the swing arm is provided with the tension sensor, the servo motor and the driving wheel system, and is driven by the rotary shaft to rotate by taking the bearing seat as a supporting point; a rotary angle of the swing arm is reflected through the tension sensor, and a signal is transmitted to the servo motor and used for adjusting the rotary speed of the servo motor in an online manner, so that the traction speed of the driving wheel system is changed; the driving wheel system is mounted on a piston rod at the head of the air cylinder, and a relative distance between the driving wheel system and the driven wheel system is adjusted along with the retraction of the air cylinder so as to clamp the loose tube, so that the loose tube is compressed; the driven wheel system and the bearing seat are fixed on a rack; and the driving wheel system and the driven wheel system are provided with traction belts and pressing wheels.