Abstract:The hydraulic system of the integral compound bulging device for driving axle housing was introduced, which was mainly composed of oil source module, control module, actuator and auxiliary components. Electrical automatic program control was used to realize inching, semiautomatic and fullautomatic control operations. Reasonable hydraulic circuits such as speed regulation, voltage regulation, reversal, action sequence and interlocking were used to meet the functional requirements of open pump circulation system.Hydraulic transmission was used to drive the combined loadbearing of outer mold and internal model components, and the loadsensitive volume throttle combined speedregulating control system was composed of pressure limiting variable pump, proportional electromagnetic reversing valve and shuttle valve network feedback oil circuit, by which the energy utilization and comprehensive performance of the system was improved and the compound linkage of ninebar mechanism was realized. Displacement, velocity and pressure feedback were combined for closedloop control, and the control accuracy of the system was improved; the continuous, stable and reliable elastoplastic deformation of the slotted heating tube billet was realized, and the qualified semifinished products of the drive axle housing were obtained