With the development trend of constant speeding and heavy loading of the railway transportation, the freight train wheels which take the way of touching area breaking are in the bad conditions of strong friction, fever load and big wheel track forces. After many times’ repeated breaking, the wheels will come to be thermal fatigue, then, result in expired puncture. In this article, according to the actual work condition of the freight train wheel, its temperature and stress fields in the process of an urgently breaking when the wheel speed is 120 km/h with the 21 tons shaft weight were analyzed and simulated by Finite Element Method. The relationship between the injury occurring on the touching area of freight wheel and the fields of the temperature and stress was also studied. The research results showed that the maximum values of the temperature and thermal stress lied in the breaking process all locate in the touching friction area between the breaking and the wheel, and the temperature rises continuously with the breaking process going on. When the value of the temperature gets to the crest value, it slowly descends. The wheel temperature reduces from the touching area to the wheel shaft, and the nearer of the distance to wheel shaft, the lower of the temperature and stress values. After the end of the breaking process, the temperature into the wheel is higher than that on the touching area, and the maximum stress exists under the wheel touching area.