The invention provides a redundant power supply switching circuit structure and method of a vehicle-mounted TBOX, and the structure comprises a main power supply input interface circuit, a main power supply step-
down conversion circuit, a dynamic
voltage monitoring and switching circuit, a standby battery input circuit, a battery boost circuit, and a vehicle-mounted TBOX
system. The output end of the main power supply input interface circuit is electrically connected with the input end of the main power supply step-
down conversion circuit and the input end of the dynamic
voltage monitoring and switching circuit, and the output end of the main power supply step-
down conversion circuit is electrically connected with the vehicle-mounted TBOX
system. The output end of the dynamic
voltage monitoring and switching circuit is electrically connected with the input end of the battery input circuit, the output end of the battery input circuit is electrically connected with the input end of the battery booster circuit, and the input end of the battery booster circuit is electrically connected with the vehicle-mounted TBOX
system. According to the vehicle-mounted TBOX power supply, contactless switching, a
semiconductor switch, multi-stage protection and a redundant framework are triggered through dynamic voltage monitoring, and the problems of low efficiency, high
delay, electric leakage, reverse charging and the like in traditional vehicle-mounted TBOX power supply switching are solved.