Hydraulic combination window opening tool

The utility model relates to a hydraulic combined window opening tool in the field of down-hole drilling tools; the tool comprises a milling cone and a whipstock; the milling cone is arranged on the upper end of the whipstock; the upper end of the whipstock is an inclined iron; bosses are arranged at different positions up and down on the upper end of the inclined iron; the head of the milling cone is stuck between the two bosses sidewards; the lower end of the milling cone and the upper end of the inclined iron are connected with a stable screw which is arranged sidewards; the milling cone and the inclined iron are respectively provided with eccentric through holes; the two eccentric through holes are connected by a pressure transmitting pipe; the inclined iron and the pressure transmitting pipe are connected by a shear pin which is arranged sidewards; and the lower end of the pressure transmitting pipe is provided with a ball seat. The tool is lowered at a window opening position of a sleeve in a well, pressurizes through the eccentric through holes so that the whipstock is sealed, and then separates the milling cone and the whipstock through ground pitching, drilling tool rotating and other processes, lowers a drill string and then opens the window with the milling cone. The device is lowered into the well and can open the window with the sleeve at one time, improves the working efficiency, saves expense, and can be applied in petroleum drilling and exploitation.