The invention provides an automobile-used electrical control vacuum booster which is divided into a front cavity and a rear cavity through a membrane, wherein a normally open vacuum solenoid valve and a normally closed air solenoid valve are arranged on a casing of the rear cavity. When a driver does not tread on a brake pedal, the front cavity is communicated with a suction manifold of an engine through a vacuum tube and the rear cavity is communicated with the suction manifold of the engine through the vacuum solenoid valve so as to keep pressures of the front cavity and the rear cavity balanced; in addition, the vacuum solenoid valve and the air solenoid valve are powered on under the control of a brake switch after the driver treads on the brake pedal, the vacuum solenoid valve is switched off to lead the rear cavity and the suction manifold of the engine not to be communicated, the air solenoid valve is switched on, external air is charged in the rear cavity to lead the pressure of the rear cavity to raise, the membrane is pushed to move forwards, and a brake assisting power is applied to a piston of a brake master cylinder through a push rod of a booster. When the electrical control vacuum booster is damaged, manual braking can be performed normally. The automobile-used electrical control vacuum booster simplifies the internal structure of a traditional vacuum booster, and can lower the manufacturing cost and the maintenance cost of the vacuum booster.