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The brake-by-wire（BBW）actuator is a modern form of actuator that replaces some of the mechanical and hydraulic components of conventional actuators completely or partially with the electronic control components and uses cables and wires as a medium of energy and signal transfer.Fast response,precise control,and a compact structure are the advantages of BBW actuators.However,the BBW actuators are still in their progressive development,and since they operate in severe conditions like the electromechanical brake（EMB）system and this may cause the entire brake system to malfunction.Therefore,there is still a need for further improvement and development of new brake mechanisms in the vehicle industry due to the everincreasing demand for better safety and performance.This thesis proposes the principle of a novel integrated BBW system for achieving continuous and rapid braking force performance of EMB across the entire operating range.The proposed BBW actuator is composed of an AC servo motor,a planetary gear set,a magnetic powder clutch with quick response and a wide range of controllable transmission torque,and a screw set.The planetary gear set amplifies the motor output torque before transferring it to the magnetic powder clutch.The actuator can provide real-time control of the braking force at the end of the screw set by controlling the input applied current to the magnetic powder clutch excitation coil.In this study,the actuator braking torque is matched for an electric scooter vehicle,and a test bench for the principle validation is built.To evaluate the magnetic powder clutch mechanical response characteristics,the rotational output torque calibration experiment and the braking force response time tests are evaluated.Finally,the hierarchical control strategy is designed considering the AC servo motor and magnetic powder clutch.The real-time tracking control of the output braking force of the ball screw mechanism has been studied and explored in detail.