Abstract: The safety, comfort and wheel rail dynamic characteristics of high-speed railway train running are highly correlated with the line shape and length of the transition curve. The high-speed railway train-line system model was built by dynamic analysis software SIMPACK. Considering the rail surface irregularity of high-speed railway, the low interference spectrum was introduced to study the influence of the line shape and transition curve length on main evaluation indexes when the high-speed train was moving. The research shows that when the curve radius of reaches 7000m or more and the transition curve reaches a certain length, the three parabola type transition curve has little difference compared with the half wave sine type for the high speed train above 300 km/h.