For the active safety performance of heavy-duty vehicles， the dynamic performance of the hydraulic brake-by-wire for heavy-duty vehicle braking process is studied. The principle and working mode of the hydraulic brake-by-wire are analyzed and the key hydraulic components of the system are mathematically modeled. The hydraulic model of the hydraulic brake-by-wire system is established in the AMESim. The accumulator pressure maintaining control strategy and the wheel cylinder pressure following control strategy based on PID algorithm are designed. The control strategy is embedded in the electronic control unit and the HBW test bench is developed. Under typical braking conditions， the dynamic characteristics simulation and test verification of wheel cylinder pressure are carried out. The results show that the established hydraulic model is accurate， and the hydraulic brake-by-wire system is effective with quick dynamic response and high precision.