Numerically-controlled machine tool for machining bearing main spindle of railway vehicle

The invention discloses a numerically-controlled machine tool for machining a bearing main spindle of a railway vehicle. The numerically-controlled machine tool comprises a machine tool body which comprises a left power main spindle box (2), a right power main spindle box (3) and a clamping transmission chuck (4), wherein an ejector pin (5) is arranged in the center position of the clamping transmission chuck (4); a four-claw clamping device is arranged on the circumferential line of the clamping transmission chuck (4); a cutting upper assembly is arranged between the left power main spindle box (2) and the right power main spindle box (3). According to the numerically-controlled machine tool for machining the bearing main spindle of the railway vehicle, the ejector pin (5) and a workpiece clamping device of the four-claw clamping device are integrated on the clamping transmission chuck (4) of the machine tool body, the mechanical machining requirements on circumferential sides and planes are met by means of switching the clamping manner of the ejector pin (5) and the four-claw clamping device, and the situation that the ejector pin (5) and the four-claw clamping device are only used is avoided, so that the workpiece clamping times are reduced, and the mechanical machining precision is improved.