The application provides a
backup flight control method, device and
system suitable for a civil
branch passenger plane, belonging to the technical field of flight control. A
backup flight control computer receives a switch on-off
signal from a
backup flight
control system pre-position switch in a
cockpit in real time. When the pre-position switch is in a pre-position state, the backup flight control computer accesses the power supply of a backup
control system independent battery. The backup flight control computer starts and receives a control instruction in real time to obtain an
actuator control instruction. The backup flight control computer receives a switch on-off
signal from an enable switch in real time and quickly outputs the
actuator control instruction to the
actuator when the enable switch is in an enable state. The actuator controls a control surface based on the actuator control instruction to control the flight of the plane. In the application, when a
pilot monitors that the main flight
control system cannot safely control the plane, the backup flight control
system can be quickly switched to, so that the stable control of the attitude of the plane is realized.