Under the trend of speeding up of freight trains on existing railway, in order to study the influence of the position of without braking function on the safety of empty freight trains, a dynamic model of the Train-Track coupling system was established based on the theory of vehicle system dynamics and the theory of Vehicle-Track coupling dynamics. And the safety indicators of the empty freight train’s lateral wheelset force, derailment coefficient, and wheel unloading rate were analyzed and compared with the dynamic safety indicators of the empty freight trains with braking function, while the vehicles without braking function located in the front, middle and rear parts of the empty freight train with the initial braking speed increased from 80 km/h to 90 km/h. The results show that during the service brake conditions, whether there are vehicles without braking function or not, the safety performance of the empty freight train is not much different, and they all meet the requirements of the GB/T 5599-2019 standard of ‘Specification for dynamic performance assessment and testing verification of rolling stock’, and the safety performance of the vehicles without braking function is not significantly different from that of the normal vehicles, the lateral wheelset force and the derailment coefficient are slightly greater than those in other parts while the vehicles without braking function located at the front part of the train, and the dynamic performance is not much different when the vehicles without braking function located in the middle and rear of the train.