The construction and opening of domestic subway lines have increased in recent years. However, early abnormal damage of switch rails in a newly opened line is common and causes hidden dangers to the safe operation of the trains and the lines. Through an investigation of the early damage of switch rails in new subway lines, we determine that the damage type of the subway switch rail is contact fatigue damage. The damage features and characteristics are studied in depth and combined with the wheel-rail relationship, structural characteristics, running characteristics, switch rail type, and top slope of the turnout. Influencing factors such as the track elasticity are analyzed. The main reason for the occurrence of rail head contact fatigue damage is that the wheel-rail contact stress is too large, and the operating conditions of a consistent new wheel are the main reason for the damage. The following measures to delay early damage to a subway is therefore proposed: to improve the wheel-rail relationship, to improve the operating conditions, to improve the material performance, and to enhance maintenance.