In this study, the hot forging process of spline hub was simulated using the finite volume method. The proposed simulation model was compared with experimental samples and approved. Then, stress analysis of the rigid die was undertaken using the finite element method. On the basis of proposed model, the full factorial design of experiments was performed for investigating the influence of forging temperature and flash thickness on the die fatigue life. Results show that the increase in forging temperature and flash thickness, both cause the increase in the fatigue life. It is also shown that the effect of forging temperature on the fatigue life is greater than that of flash thickness. In drop-hammer forging, when number of blows decreases, the die fatigue life increases considerably.