The invention relates a fixed wheel assembly, specifically relates to a fixed wheel assembly of a pipe bending machine, and belongs to the technical field of pipe bending machines. The fixed wheel assembly of the pipe bending machine comprises a fixed wheel shaft; a fixed gear is arranged at the lower part of the fixed wheel shaft; an upper pressing plate and a lower supporting plate are connected to the upper part of the fixed wheel shaft from top to bottom in a sequence; the fixed wheel is respectively connected with an upper bearing block and a lower bearing block through an upper bearing and a lower bearing; the upper bearing block and the lower bearing block are respectively positioned at the upper end and the lower end of the fixed gear. The fixed wheel assembly of the pipe bending machine is simple, compact and reasonable in structure; when in working, a workpiece is clamped through the upper pressing plate and the lower supporting plate, so that the pipe bending machine can stably work for bending, the working efficiency is increased, and the cost is relatively low; the distance from the upper pressing plate to the lower supporting plate can be adjusted to meet the requirement on bending the workpiece of different size, and therefore, the applicable scope is expanded.