In this paper, a new heating control method of rail AC flash welding based on current feedback is realized by fixing PLC scanning period and servo solenoid valve. The moving end clamp of welding machine head is superimposed with a variable speed feed motion on the basis of fixed vibration, so as to realize the rapid and high-quality heating of the rail end surface. The temperature field of the original pulse heating process is collected by infrared thermal imager and compared with that the new heating process before the end of high voltage stage. The results show that under the same heating time, the width of the high temperature zone of the new heating control method increases by more than 13.82% compared with the original pulse flash welding. Combining with the welding curve, it can be seen that the new heating control method increases the thermal efficiency by increasing the minimum current and reducing the circuit breakage, which can quickly establish the width of the temperature field at high temperature.