In order to more accurately describe the following behavior of vehicles in the freeway shunt zone, this paper introduces the lane change pressure gain factor based on the FVDM model to construct a following model that considers lane change pressure and lane change behavior. First, the linear stability analysis of the improved model reveals that the stability region of the freeway shunt area becomes smaller with the increase of the lane change gain factor. Second, the improved model is calibrated based on the trajectory data of 92 lane-changing vehicles extracted from the NGSIM dataset, and the simulation analysis shows that the improved model can better simulate the speed and position of the vehicles, and the simulation error of the constructed P-FVDM model is reduced by 16% compared with that of the FVDM model; the simulation error of the constructed PLP-FVDM model is reduced by 16% compared with that of the LP-FVDM model; and the simulation error of the constructed PLP-FVDM model is reduced by 16% compared with that of the LP-FVDM model. model reduces the simulation error by 12% compared to the LP-FVDM model. Finally, the improved FVDM model is used to simulate and analyze the traffic oscillation phenomenon in the diversion area, and the results show that the traffic oscillation can be triggered by the lane changing behavior of vehicles, and the amplitude of the traffic oscillation will be attenuated at higher driving speeds, and the standard deviation of the speeds will show a concave growth trend along the convoy to the upstream when the driving speeds are lower; the closer the position of the lane changing to the exit ramp is, the more serious traffic oscillation is triggered; and the shorter the duration of the lane changing is, the better it is for suppressing the traffic oscillation. The shorter the duration of lane change is, the more favorable it is to suppress the traffic oscillation.