Abstract: There are several factors that increase the likelihood of yaw instability with a loaded tractor semi-trailer. Lateral instability phenomena will likely occur in tractor semi-trailers on high speed obstacle avoidance under emergency or during high speed curve driving. The linearized three-axle model is utilized to predict the dynamics state of the tractor semi-trailer built in multibody dynamics simulation software. The lateral stability simulation was performed on the dynamic model based on virtual prototyping. The results show that the lateral stability control based on sliding mode control proposed in this paper can stabilize the tractor semi-trailer, prevent from rollover on high speed obstacle avoidance under emergency or during high speed curve driving.