During the braking process of heavy-duty hybrid vehicles, it is necessary to quickly and smoothly switch between electric motor braking and hydraulic braking, which requires the braking system to have a high degree of dynamic response capability and precise control strategy. However, when the vehicle is in an emergency braking state, the ABS system also triggers and interrupts the motor braking force to ensure that the wheels do not lock up, which causes brake force fluctuations. In order to maintain braking stability after ABS triggering, a collaborative control strategy needs to be designed to achieve a smooth transition between the motor and hydraulic braking. Therefore, a layered multi-mode joint braking cooperative control method is proposed for heavy-duty hybrid electric vehicles. Perform multi-sensor data fusion processing on the speed, wheel speed, and acceleration data of heavy-duty hybrid vehicles, and calculate the wheel slip ratio of heavy-duty hybrid vehicles based on the multi-sensor fused speed and wheel speed data. Build a longitudinal dynamic equation for a heavy-duty hybrid electric vehicle based on multi-sensor fusion acceleration data, and calculate the road adhesion coefficient during driving using wheel slip ratio and longitudinal dynamic equation. Design a joint braking collaborative control method for heavy-duty hybrid electric vehicles under different operating conditions, and introduce a layered control mode to achieve smooth transition and coordinated control of the braking system under the condition of completely exiting the motor braking force after ABS triggering, reducing the frequency of braking force fluctuations; Under the condition of reducing the motor braking torque to the steady-state range after ABS triggering, the distribution strategy of the motor and hydraulic braking force after ABS activation is determined based on the road adhesion coefficient to achieve coordinated control of composite braking; Under the condition of exiting the motor braking force before ABS triggering, dynamically adjust the distribution of motor braking force and hydraulic braking force based on the predicted ABS lock up trend to ensure a smooth transition to the appropriate braking mode. The test results show that under all three operating conditions, the design method can maintain a low braking distance, with a maximum of no more than 133m. The battery SOC recovery rate is high, reaching up to 65%, and the motor torque changes are relatively stable, without short-term large and frequent fluctuations.