A three-axle heavy-duty vehicle model was built based on the TruckSim vehicle simulation software in order to improve the safety performance of the vehicle under the steering braking condition.The mechanical properties of three-axle vehicles under steering braking conditions were analyzed.Based on the analysis results, a three-axis vehicle steering brake cooperative controller was designed by reducing braking force.A fuzzy controller for slip ratio distribution was designed for the case that the vehicle was understeering.The control effect of ABS control and coordinated control under steering braking conditions were examined by using co-simulation with TruckSim and Simulink.The simulation results show that the coordinated controller improves the steering stability and braking safety of the three-axle heavy-duty vehicle compared with the ABS controller under steering braking conditions.