The invention discloses a special-purpose device for rapidly detecting a seepage point of a single tube type electric generator oil cooler. The special-purpose device comprises a cooler, a pressing device, an air inlet tube and a pressure gage, wherein an air inlet opening of the cooler is provided with an inlet air chamber, an air outlet opening of the cooler is provided with an outlet air chamber, discoid pressure discs are respectively mounted on bottom parts of the inlet air chamber and the outlet air chamber, and the pressure discs are provided with detection openings; the inlet air chamber and the outlet air chamber are respectively provided with an air inlet tube, an air outlet tube and valves; an air inlet pressure measuring tube and an air outlet pressure measurement tube are respectively arranged in the inlet air chamber and the outlet air chamber; according to the special-purpose device, an oil inlet opening and an oil outlet opening of the cooler are pressed, whether a seepage problem occurs in an inner part of the cooler can be rapidly determined, a seepage point can be positioned and determined, the pressure gage is welded on a flange of an air outlet end, and a valve is welded on a flange of a pressing end; when pressing end presses with a test pressure, the valve is closed, and effects exerted on pressure maintaining condition by a pressing pump and flexible tube seepage can be eliminated.