The invention discloses a pipe straightening device, and relates to the technical field of straightening machinery. The pipe straightening device comprises a support, a sealing cover, a straightening device, a pushing mechanism, a detection device, a pushing block and a pipe, wherein the sealing cover is fixedly mounted at the top of the support, the pushing mechanism is mounted below the support, the detection device is mounted at the bottom of the pushing mechanism, the pushing block is installed at the bottom of the pushing mechanism, the pipe is placed on the upper portion of the support, the straightening device is installed on the upper portion of the support, and the straightening device comprises a rotating cylinder and a rotating shaft. According to the pipe straightening device, through cooperative use of the rotating cylinder, a flexible connecting mechanism, a forging mechanism and a cooling mechanism, the problem that an existing device cannot straighten a pipe from the inner side and the outer side of the pipe wall is solved, the rotating cylinder is driven to rotate through a motor, and the rotating shaft is driven to rotate and extend through a spiral groove and a pin, and therefore, the extending movement of the forging mechanism and the cooling mechanism is realized.