Train/turnout dynamic interaction is exacerbated by high speed of passenger train and heavy load of freight train, and wheel/rail relation is one of the key factors that determine the running characteristics of the train. Focusing on three types of wheel treads with different profiles (TB tapered tread, LM worn tread, LMA worn tread), longitudinal distribution of the contact geometric parameters along the switch rail and nose rail of 350km/h No.18 turnout are calculated, such as tread equivalent conicity, coefficient of contact angle difference, roll angle factor, gravitational stiffness of wheelset, gravitational angle stiffness of wheelset, etc. Results show that: (1) LMA worn tread produces the smallest irregularity; (2) wheel/rail vertical impact at the frog will become bigger; (3) Top profile of switch rail and nose rail should be designed according to the wheel tread type so as to mitigate the wheel/rail dynamic interaction and increase the safety and stability of a train.