Abstract: Described here in the essay is the application of the PROFIBUS field bus-based PLC control system to the hydrostatic testing machine.Moreover,detailed are the configuration of the system and the PROFIBUS hardware configuration,the network configuration and software design,also involving relevant software such as STEP 7 and WinCC,etc.The actual application result shows that the said control system is in possession of such advantages as operation reliability,easy maintenance and satisfactory control performance,having been capable of completely meeting the specified requirements for control of the hydro-testing machine.