A brake system for a four-wheel drive electric vehicle, comprising: a vehicle controller, comprising a first brake control unit and a second brake control unit; a signal detection sensor, configured to detect a brake pedal depth signal and a vehicle speed signal; and a motor controller, wherein, the first brake control unit is configured to determine a brake mode of the electric vehicle according to the brake pedal depth signal, to determine whether a current value of a state of charge for a battery pack of the electric vehicle is greater than a preset value of the state of charge and to determine whether a vehicle speed value of the electric vehicle is less than a preset vehicle speed value according to the vehicle speed signal, wherein the brake mode of the electric vehicle comprises a first brake mode and a second brake mode; the motor controller is configured to control a motor of the electric vehicle to regeneratively brake a wheel of the electric vehicle when the electric vehicle is in the first brake mode, the vehicle speed value is greater than or equal to the preset vehicle speed value and the current value of the state of charge is less than or equal to the preset value of the state of charge; and the second brake control unit is configured to control a brake actuator of the electric vehicle to brake the wheels of the electric vehicle when the electric vehicle is in the first brake mode and the vehicle speed value is less than the preset vehicle speed value, or when the electric vehicle is in the first brake mode and the current value of the state of charge is greater than the preset value of the state of charge, or when the electric vehicle is in the second brake mode, characterized in that the signal detection sensor is further configured to detect a brake pressure signal; the first brake control unit is further configured to determine whether a brake torque of the brake actuator on the wheels fails in a braking process for the wheels by the brake actuator according to the brake pressure signal; and the motor controller is further configured to control the motor to regeneratively brake the wheel when the brake torque of the brake actuator on the wheels fails and the vehicle speed value is greater than or equal to the preset vehicle speed value and the current value of the state of charge is less than or equal to the preset value of the state of charge, and to control the motor to reversely brake the wheel when the brake torque of the brake actuator on the wheels fails and the vehicle speed value is less than the preset vehicle speed value, or when the brake torque of the brake actuator on the wheels fails and the current value of the state of charge is greater than the preset value of the state of charge. a vehicle controller, comprising a first brake control unit and a second brake control unit; a signal detection sensor, configured to detect a brake pedal depth signal and a vehicle speed signal; and a motor controller, wherein, the first brake control unit is configured to determine a brake mode of the electric vehicle according to the brake pedal depth signal, to determine whether a current value of a state of charge for a battery pack of the electric vehicle is greater than a preset value of the state of charge and to determine whether a vehicle speed value of the electric vehicle is less than a preset vehicle speed value according to the vehicle speed signal, wherein the brake mode of the electric vehicle comprises a first brake mode and a second brake mode; the motor controller is configured to control a motor of the electric vehicle to regeneratively brake a wheel of the electric vehicle when the electric vehicle is in the first brake mode, the vehicle speed value is greater than or equal to the preset vehicle speed value and the current value of the state of charge is less than or equal to the preset value of the state of charge; and the second brake control unit is configured to control a brake actuator of the electric vehicle to brake the wheels of the electric vehicle when the electric vehicle is in the first brake mode and the vehicle speed value is less than the preset vehicle speed value, or when the electric vehicle is in the first brake mode and the current value of the state of charge is greater than the preset value of the state of charge, or when the electric vehicle is in the second brake mode, characterized in that the signal detection sensor is further configured to detect a brake pressure signal; the first brake control unit is further configured to determine whether a brake torque of the brake actuator on the wheels fails in a braking process for the wheels by the brake actuator according to the brake pressure signal; and the motor controller is further configured to control the motor to regeneratively brake the wheel when the brake torque of the brake actuator on the wheels fails and the vehicle speed value is greater than or equal to the preset vehicle speed value and the current value of the state of charge is less than or equal to the preset value of the state of charge, and to control the motor to reversely brake the wheel when the brake torque of the brake actuator on the wheels fails and the vehicle speed value is less than the preset vehicle speed value, or when the brake torque of the brake actuator on the wheels fails and the current value of the state of charge is greater than the preset value of the state of charge.