The two bar billets with different height-diameter ratio in enterprise were studied on the process of gear blank thermal forming. The rigid-viscoplastic finite element simulations in multifactor coupling condition of stress ,heat and wear were established. The metal flow in the process was simulated. The temperature distribution and varying of the mold and blank was forecast. The single-step wear depth and distribution of the die in forging was analysed based on Archard ,which provided sufficient data to evaluate life of the die. The reasonable aspect ratio for blank can be obtained upon the results, which will offer basis to the product.