The simulation package for special research on derailment of high speed vehicle is established.The process of derailment is different from other behaviors of vehicle dynamics because of large lateral displacement of wheelsets.To get correct results,a new fast algorithm to computing contact force is adopted and the exact geometry analysis is necessary to judge derailment happened.Variation of contact condition and coefficient of friction with speeds are also considered into vehicle-track coupled model.The structure of the package is presented in detail.The results are particular emphasis on investigation influence of maximum track defect,critical vehicle speed and various contact condition on derailment.The simulation can also be used to define the most risk factor leading to derailment. The simulation package for special research on derailment of high speed vehicle is established from process behaviors of derailment is different from other behaviors of vehicle dynamics because of large lateral displacement of wheelsets. To get correct results, a new fast algorithm to computing contact force is and the exact geometry analysis is necessary to judge derailment happened. Variation of contact condition and coefficient of friction with speeds are also considered into vehicle-track coupled model. Structure of the package is presented in detail. The results are particular emphasis on investigation influence of maximum track defect, critical vehicle speed and various contact conditions on derailment. simulation can also be used to define the most risk factor leading to derailment.