The invention discloses an outer cone grinding centering fixture. The outer cone grinding centering fixture is characterized in that a fixture body is made of spring steel, a center hole of the fixture body is a double-section combination hole, and a left threaded hole section and a right oil injection hole section are connected with each other to form the center hole; a plug is arranged at the threaded hole section of the center hole of the fixture body, and the right portion of the plug extends into the oil injection hole section of the center hole; the fixture body is of a four-section stepped shaft structure and sequentially comprises a first cylinder section, a second cylinder section, a third cylinder section and a fourth cylinder section from the left to the right, the diameters of the first cylinder section, the second cylinder section and the third cylinder section are gradually increased, and the diameter of the fourth cylinder section ranges from the diameter of the second cylinder section to the diameter of the third cylinder section; at least three counter-bored holes are peripherally uniformly formed in the third cylinder section of the fixture body, a radial hole is further formed in the third cylinder section, an oil return pipe is connected to an outer orifice of the radial hole by screws, and the inner end of the radial hole is communicated with the middle of the oil injection hole section of the center hole of the fixture body. The outer cone grinding centering fixture has the advantages that workpieces can be effectively centered by the aid of the outer cone grinding centering fixture, and the outer cone grinding centering fixture is high in centering precision.