The invention provides a steel rail flash welding machine with interrupted center shafts. The flash welding machine comprises a movable frame, a fixed frame, a first clamping device, a second clamping device and a control device. The movable frame and the fixed frame stretch over the positions, close to the welding section, of two to-be-welded steel rails in the steel rail width direction correspondingly. The movable frame and the fixed frame are connected through upsetting shafts, and the movable frame can move towards the fixed frame along the upsetting shafts. The first clamping device is connected with the movable frame so as to drive the movable frame to be opened and closed around the first center shaft. The second clamping device is connected with the fixed frame so as to drive the fixed frame to be opened and closed around the second center shaft. The control device is connected with the upsetting shafts, the first clamping device and the second clamping device so as to control action of the steel rail flash welding machine. According to the steel rail flash welding machine, the interrupted center shafts are adopted so that large space can be reserved between the movable frame and the fixed frame to be used for mounting of other equipment, and the problem that the center shafts suffer from severe splashing is avoided.