This paper presents a new type of automotive braking actuator for a kind of brake-by-wire system called decentralized electro-hydraulic braking system( DEHB) to replace the traditional automobile braking system. The actuator of this system is driven by an electrical motor instead of the conventional vacuum booster to make the brake pressure be linearity controlled quickly. Therefore,the system has the advantages of quick response speed,good control performance and simple structure. Firstly,an overview of the actuator and the whole DEHB system is shown. Secondly,the possibility of this new kind of actuator working for the system is ensured based on some braking theories. Thirdly,the appropriate dynamic simulations are done to get some results to show the relations of different parameters and the effect of braking. Eventually,the proper parameters are determined to build a test bench which shows that DEHB system can achieve the maximum pressure of 13 MPa within 100 ms after parametric optimization,and meanwhile,the actuator is able to reduce pressure quickly after maintaining high pressure. All of the bench test results can meet with the design requirements and real demand of vehicle and this actuator may improve vehicle braking effect in the future. Besides,this actuator can be widely applied to the regenerative braking system because of its linear braking performance. The paper presents a new type of automotive braking actuator for a kind of brake-by-wire system called decentralized electro-hydraulic braking system (DEHB) to replace the traditional automobile braking system. The actuator of this system is driven by an electrical motor instead of the conventional vacuum booster to make the brake vacuum be linearity controlled quickly. Therefore, the system has the advantages of quick response speed, good control performance and simple structure. Third, the appropriate dynamic simulations are done to get some results to show the relations of different parameters and the effect of braking. Eventually, the proper parameters are determined to build a test bench which shows that DEHB system can achieve the maximum pressure of 13 MPa within 100 ms after parametric op timization, and meanwhile, the actuator is able to reduce pressure quickly after maintaining high pressure. Apart, the this design requirements and real demand of vehicle and this actuator may improve vehicle braking effect in the future. actuator can be widely applied to the regenerative braking system because of its linear braking performance.