In order to analyze the effect of the number of empty trains on the safety of freight trains, a dynamicmodel of the train -track coupling system with empty vehicles and heavy vehicles was established based on thetheory of vehicle system dynamics, train longitudinal dynamics theory and the theory of vehicle-track couplingdynamics. Based on this, the lateral wheelset force, the derailment coefficient, the wheel unloading rate were an-alyzed when different numbers of empty vehicles were located in the head and rear parts of the freight trainwhile braking. The results show that when 5, 10, and 20 empty vehicles at the head and tail of the train, the lat-eral wheelset force, the derailment coefficient, the wheel unloading rate of the empty and heavy vehicles all meetthe standard requirements of the GB/T 5599- -2019 standard and there is a certain safety margin. When the emptyand heavy vehicles mixed marshalling train braking on curve railway, the lateral wheelset force of the empty ve-hicle is less than that of the heavy vehicle, and the derailment coefficient and wheel unloading rate of the emptyvehicle are greater than that of the heavy vehicle. When 5 empty vehicles at the head and tail of the train, thelateral wheelset force of the empty vehicle and the heavy vehicle are all the minimum, but the wheel unloadingrate of the empty vehicle at the tail is the largest at the same time. For the derailment coefficient and wheel un-loading rate, except for the case of only 5 empty vehicles located in the head and rear marshalling, the derail-ment coefficient and wheel unloading rate of the empty vehicles marshalling at the head of the train are higherthan those at the tail. When the head and tail of the train are marshalling of 10 and 20 empty vehicles respec-tively, the difference in the overall wheel load reduction rate of the two trains is small.