Three-dimensional drafting device of spinning machine

The utility model provides a three-dimensional drafting device of a spinning machine. By means of the three-dimensional drafting device of the spinning machine, the quality of a strand can achieve the quality of a resultant yarn in a spinning process. The three-dimensional drafting device of the spinning machine comprises a front roller pair composed of a front upper roller and a front lower roller, a front middle roller pair composed of a front middle upper roller and a front middle lower roller, a rear middle roller pair composed of a rear middle upper roller and a rear middle lower roller, and a rear roller pair composed of a rear upper roller and a rear lower roller. The front lower roller is mounted on a front lower roller sliding seat, the front middle lower roller is mounted on a front middle lower roller sliding seat, the rear middle lower roller is mounted on a rear middle lower roller sliding seat, and the rear lower roller is mounted on a rear lower roller sliding seat. A first pin roll is arranged