The invention discloses an electro-hydraulic brake system driven by a motor for a vehicle. The electro-hydraulic brake system comprises a brake pedal, a pedal displacement sensor, a hydraulic sensor, a pedal simulator, a pedal push rod with two branches, an electric control unit, an electric control linear motion module, a brake main cylinder, a secondary main cylinder and an ABS (anti-lock braking system) / ESC (electronic stability control) module; one branch of the pedal push rod is abutted against the linear motion mechanism, and is positioned in the same axis as the piston of the brake main cylinder; the other branch of the pedal push rod is connected with the piston of the secondary main cylinder; the brake main cylinder sequentially comprises a front cavity, a first cavity and a second cavity for the brake main cylinder; the front cavity is connected with the secondary main cylinder and a liquid storage tank respectively through a decoupling valve and a liquid supply valve; the first cavity and the second cavity are connected with a vehicle wheel brake through the ABS / ESC module; the secondary main cylinder is connected with the liquid inlet of the pedal simulator. The electro-hydraulic brake system is used for recycling brake energy, improving system response time and accurately controlling hydraulic brake force, well feeds the braking force back to a driver, and realizes active control over hydraulic force and pedal force of the system.