In the production process of the giant tire, the tire unloader needs to clamp and flip the tire, and the tire has a large inertia force, easy to cause vibration and lead to the failure of bearing parts, etc., then the flange is needed to play a fixed role. therefore, the rationality of flange design for the use of safety and service life are very important. For this reason, this paper simulates the flange connected to the tire unloader to obtain its stress history data, at the same time through genetic algorithm structure optimization analysis was carried out on the flange, it is concluded that the influence of structure parameters on the life of flange, and flange for structure optimization, get the optimized flange fatigue life 71 % increase compared to the original plan. The weight is reduced by 0.9 %, and the mechanical properties of the optimized flange are better.