The present disclosure provides a backlight driving circuit, a liquid crystal display (LCD) device, and a driving method. The backlight driving circuit includes a monitoring device and a conversion device, the conversion device includes a microcontroller (MCU) and a switch module. A control end of the switch module is coupled to the monitoring device, and the monitoring device outputs a monitoring signal to turn on or turn off the switch module. An input end of a power source of the MCU is coupled to a power end of the backlight driving circuit through the switch module.