In terms of the pressure and weight of large cylinder forgings, there are many representative products such as water reactor pressure vessels produced by major cylinder forgings in the world. In 2005, two Chinese companies in the large cylinder forging in the forging process, more and more heavy group use temporary demolition of hydraulic press pillar sheath, the open files size depending on the grain structure effect on the final product properties, and gradually increase to 511 m approach, successfully produce the dimensions for technological measures to refine the grain size organization, uniform grain size distribution. Among them, the pressure vessel cylinder forgings of 1900mmx5030mm broke the research method combining theoretical simulation and numerical simulation and drove the 5m size limit of the large hydraulic press with 1.12 million tons of cylinder. In April 2006, the forging technology level of one forgings has been improved rapidly. In 1987, the German Heavy Industry Group used the method of installing the auxiliary tools, the total weight of 312T KoppR, first of all, the plastic numerical simulation was divided into three layers of SA508Cl13 steel ingot forging into 650M W nuclear reactor pressure times: the first layer is the macro analysis of force, energy, work parameters; The local analysis of the distribution law of parameters such as stress and strain in the second layer.