To improve the lateral stability of tractor-semitrailer under low adhesion road surface, a direct yaw torque control strategy considering longitudinal speed control was proposed based on distributed electric drive technology. A hierarchical control strategy was designed, with the upper layer using a linear quadratic regulator (LQR) controller to calculate the yaw moment. To distribute the longitudinal force and additional yaw moment, the torque distribution method was adopted based on quadratic programming in the lower controller. The co-simulation was conducted by Trucksim and Matlab/Simulink under the conditions of single lane change (SLC) of 110 km/h and double lane change (DLC) of 70 km/h. The results indicate that in comparison with the PID controller and the uncontrolled vehicle, the LQR controller improves the lateral stability of the vehicle on the low-adhesion road.