A combination valve of proportional pressure and flow in differential pressure type consists of main valve body, proportional flow valve and guide valve for it, proportional pressure valve and guide valve for it as well as safety valve and it is built as setting external round slot at the up end part of valve pocket for pressure valve, setting internal round slot at the corresponding place of the external round slot as a number of oil entrance distributed uniformly in radial direction on it and setting vertical oiling channel g which is connected with operational oil hydraulic p entrance through lateral oiling channel h and vertical oiling channel a at the place corressponded to the external round slot in the main valve body. It has overcome the defect of pressure relief of hydraulic oil between the main valve core and the main valve pocket of the current product. |