Using Forge 2D/3D forging finite element simulation software, the forging environment and deformation process of large forging case were simulated and analyzed. The influences of forging temperature,die design, forging equipment and other factors on the forging blank were discussed. The stress and strain, rule of metal flowing, forging flaw, metal lines, the final geometrical shape of finished forging, etc. during forging were analyzed. The important parameters, such as the weight of cropping, forging energy, heating times, die design,etc. in forging technology design were determined，which provide a reference for forging technology design in actual production.