When high-speed train wheels and turnouts (switches and crossings) experience wear, especially when worn wheels pass through the turnout area, the wheel-rail dynamic responses triggered by geometric discontinuities pose a threat to driving safety and severely affect passenger comfort, making it urgent to conduct research. By employing the finite element method, an in-depth investigation is carried out into the stress distribution, interaction, and their influence mechanisms between high- speed train wheels and turnouts, as well as the evolving laws with the changes in wheel wear and turnout geometric shapes. The study finds that the interaction between wheels and turnouts is influenced by multiple factors, including the wear states of wheels and turnouts, cumulative tonnage passed, and track geometric shapes. When a wheel passes through the turnout, as its position changes, the wheel- turnout contact stress and Von Mises equivalent stress fluctuate significantly. When the wheel moves from a position where the top width of the switch rail is 15 mm to one where it is 35 mm, the overall contact stress rises notably, with a growth rate of approximately 14.4%; the maximum Von Mises equivalent stress also shows an increasing trend, with a growth rate of about 4.1%. Wheel wear not only alters the shapes of the wheel rim and tread but also significantly affects the wheel-rail contact relationship and stress distribution. The wheel-rail contact point gradually deviates from the track center, and this deviation is positively correlated with the increase in operating mileage. The stress distribution along the depth direction becomes more uneven and is greater compared to that of a newly re-profiled wheel. Meanwhile, the changes in stress affect the wheel wear rate.