Platform thread straightening machine and shoulder straightening method

The invention discloses a platform thread straightening machine and a shoulder straightening method. The platform thread straightening machine comprise a machine worktable, a machine body and a machine head, wherein the machine body is vertically arranged on the machine worktable, the machine head is connected with the machine body and is vertical to the machine body, the machine head is provided with a fabric stitching mechanism vertical to the machine worktable, a platform is arranged under the fabric pricking mechanism, protrudes from the machine worktable and is vertical to the machine worktable, a support frame is arranged between the machine body and the platform and extends from the platform to the machine body, the support frame is provided with a support surface for supporting fabric, the support surface and the upper end surface of the platform have the same height and are mutually connected, and one end, connected with the platform, of each of the two sides of the support surface extending along the support frame is downwards bent in a circular arc-shaped surface way. The platform thread straightening machine solves the technical problems of the existing platform thread straightening machine that the operation of shoulder straightening is inconvenient, and the unevenness of fabric is easily caused. The platform thread straightening machine and the method using the platform thread straightening machine for shoulder straightening have the advantages that the operation is easy, and the fabric and the shoulder are attached and flat after the shoulder straightening is completed.