Large die forging hydraulic machine is the basic equipment to produce large die forgings for aviation and ship, to develop large military equipments and other large equipments.In order to solve the hydraulic cylinder synchronization of the large forging press experiment platform, a set of multiple hydraulic cylinder synchronization control system was developed in which PLC and Rexroth HNC were taken as control core. The synchronous control system was based on the principle of electric servo synchronous control.The test results of synchronous control of hydraulic test bench verify the performance of the system.