The heavy-duty vehicles have large transportation capacity. Gross mass and center of gravity position of the heavy-duty vehicles vary with the cargo mass and the driving condition, which affect driving safety and handling stability. Gross mass and center of gravity position of the vehicles are usually measured on fixed test platform, and the vehicles are stationary or pass the platform slowly in the measurement process. Most dynamic weighing system could not measure the center of gravity position of the vehicles. On-board mass and center of gravity of motor vehicles measurement system mainly based on the tire pressure information could measure gross mass and center of gravity position accurately in the driving process. The measurement errors of the sensors are effectively decreased by filtering collected sensor data. The relationship between the tire pressure and the tire load is built when the vehicle is stationary. Dynamic mapping relationship between multiple signals and the tire load is established to eliminate the interferences affecting the accuracy and stability of the measurement system during transportation, and could measure accurately gross mass and horizontal center of gravity position of the vehicle. On-board measurement system could reduce the test times on fixed test platform effectively. And the measurement results could be used to identify the overload and the offset load, and guide the driver to load cargoes reasonably and drive safely. The simulations are conducted to verify the effectiveness of the measurement system. The simulation results show that maximum measurement error of the tire pressure is 8 kPa and average measurement error of gross vehicle mass is 2.56% which meets ASTM-E1318 standard about dynamic weighing system. Gross mass and center of gravity position of the heavy-duty vehicles could be also used as the inputs of active safety system, which could improve the adaptability of active safety system to complex conditions.