A method for selecting lubricating grease for an axle box bearing of a motor train unit of a high-speed rail comprises three steps of: step one: detecting the physicochemical indexes of the lubricating grease; second two: detecting the extreme pressure abrasion resistance of the lubricating grease; and step three: using the lubricating grease to detect the performances of the axle box bearing of the motor train unit. The lubricating grease meeting the detection of the physicochemical indexes in the step one can enter the detection of the extreme pressure abrasion resistance in the step two; and the lubricating grease meeting the detection of the extreme pressure abrasion resistance in the two can enter the detection of the performances of the axle box bearing of the motor train unit in the step three. The lubricating grease simultaneously meeting the above three steps can be determined to be the lubricating greased selected by the axle box bearing of the motor train unit. According to the method, the method is simple and effective for selection, the selected lubricating grease is applied to the operation of the axle box bearing of the motor train unit of the high-speed rail with speed being not less than 250Km/h, and the selected lubricating grease has good mechanical stability, anti-rust property, oxidation resistance, inoxidizability, high temperature applicability, low temperature capability and lubricating property.