In view of an inquiry into the operating parameters of heavy-duty lines and the influence of wheel rail forces on vehicles passing through the low rail side corrugation zone of the transition curves, a C80 vehicle track coupled multibody dynamics model has been established based on Simpack multibody dynamics software. Random irregularities in the U. S. fifth-level track can be generated by using Matlab, with the time-domain excitation of rail corrugation before the gradual circular point overlaid as the model input, followed by a simulation of the influence of key parameters such as smoothing curve length, curve radius, superelevation, and travel speed on wheel rail forces under different wavelengths, wave depths, and corrugation states at the smoothing point. An analysis of the trend of wheel rail force variation and its maximum growth rate of a wheel-set shows that the wheel rail force on the corrugation side is greatly affected by corrugation. The lateral force on the side without corrugation is more affected by corrugation than the vertical force; in the curve parameters, the maximum growth rate of each index decreases with the increase of the speed; except for the lateral force on the high rail side, all other indexes decrease with increasing curve radius. The changes in the length and superelevation of the easing curves have no significant reducing effect on the maximum growth rate of each index, and even as the operating parameters increase, the maximum growth rate of the indicator will experience an increase instead.