Traditional U-shaped steel tie rods have disadvantages such as backward production technology, long processing cycle and low material utilization. Based on this, an integrated steel tie rod forming technology is proposed. In the integrated U-shaped steel tie rod forming technology, the U-shaped head is formed by a back extrusion process, and the blank used is called a preform. The research object of this paper is the forming of preforms. The forming process is the problem of upsetting forming with large height-diameter ratio, which is also a forming difficulty. Aiming at the preform of 35 steel tie rod U-shaped head, a three-pass heating upsetting method was proposed to prepare the preform. Using different process parameters, the DEFORM software was used to numerically simulate the forming process of the preform prepared by the three-pass upsetting method. The temperature field, stress field, load and metal streamline distribution were analyzed, and the hot forming process parameters with better forming effect were obtained, and the feasibility of forming was verified through experiments.