Differential case is one of the most important parts in automobile, which is difficult to be produced using the traditional open forging die for its complicated shape. It is hard to guarantee the forging  quality. With FE analysis of three kind differential cases forming process, optimized design of parameter and die structure were carried out and the exactitude heat extrusion project was got . The result shows that the favorable quality is in accordance with the FE analysis data, the project is reasonable and the high quality and low cost production can be achieved.