The invention provides a centralized pressure supplying method of hydraulic stations to overcome the defects that in traditional large and medium machining factories, the effective utilization rate of hydraulic stations is low, and waste of electric energy is serious. The method comprises the following steps that A, when machine tools including the hydraulic stations work with the full load, the needed maximum flow and the needed maximum pressure are counted, and the accumulated values of the maximum flow and the maximum pressure are calculated respectively; B, 20%-30% of the maximum flow accumulated value and 20%-30% of the maximum pressure accumulated value are taken as the rated flow value and the rated pressure value of a new hydraulic station; C, a pressure oil pipe and an oil return pipe are connected to the new hydraulic station, and terminal valve sets of all the machine tools are connected to the pressure oil pipe and the oil return pipe in parallel; and D, pressure is supplied to the pressure oil pipe through the new hydraulic station, the terminal valve set, corresponding to the machine tool, on the pressure oil pipe is opened according to the specific working machine tool, hydraulic branches corresponding to the machine tools need pressure maintaining by adjusting the terminal valve sets, and the terminal valve sets corresponding to the machine tools are closed when the machine tools do not work.