Embodiments of this application provide a hydraulic apparatus, a brake system, and a control method. The brake system provided in embodiments of this application includes a master cylinder, a first booster, and a second booster. The brake system provided in embodiments of this application can implement rich braking functions by using the first booster or the second booster. In addition, the brake system provided in embodiments of this application has a multi-redundancy design. This can ensure that the brake system can still meet a plurality of braking function requirements of a vehicle when a controller or a key solenoid valve fails, improve safety of the brake system, ensure pedal feeling of a driver, and bring more stable and comfortable driving experience to the driver, which is suitable for brake systems of intelligent and electric vehicles.